Similar to the Russian campaign, this would probably be counted as segmented instead of ILs?

-- Yep.

After finishing the Russian campaign speedrun, I only wanted MOAR. So I set out to routing the German campaign as well, set in world wars 1 and 2. Without access to atomic bombers, most of this campaign is a little more strategic, though siege weapons and especially transport ships still play a significant role in breaking the mission wide open.

Again, the main glitch this run abuses is the free units glitch, which works by queueing up units, then immediately refunding their build cost through the tribute window. Aside that, most of the routes were devised by using the game's scenario editor to read triggers and scripts and finding out how to abuse them.
In-game time is inconsistent with RTA, but I still use it as my main reference point for speediness.

1. Cavalry of the Sky
Objectives:
Cross the frontlines to safety.
Time: 6:56

Don't believe what the mission says, photographing the military sites is purely optional. Though, oddly enough, the devs decided that, in order to keep your army hidden until you complete that objective, they'd make them an enemy faction. This makes it rather difficult to keep Holk and Richthofen alive before they reach the tent that triggers victory, but it also leads to a rather hilarious mass suicide at the end.

This mission has tons of potential for minuscule optimizations, but most of those rely on either RNG with the enemy patrols all missing you, or simply praying the pathfinding doesn't mess up somewhere. Sub-7 in-game time was my goal, and I got it.

2. Supply and Demand
Objective:
Ensure 20 transports arrive at the docks.
Time: 24:27

The only way I can actively influence the speed of this mission is by building the first docks as fast as possible. After that, I'm fully at the mercy of transport RNG. I don't understand how it's supposed to function, but it seems like every aspect of them is random: Southern vs northern route, exact spawn location, delay until it starts moving, time until a new transport spawns. As a result, the ending times vary wildly but only by a few bare seconds. 24:27 is the fastest I've achieved and I doubt it can get too much faster.

I do try to use Frigates to nudge the transports along and make them go faster, but I cannot confirm whether this actually helps at all. Outside of that, I only have to make sure no transports die, and for the rest of the mission I just do whatever I feel like to keep myself (and viewers) entertained.

3. The Red Baron
Objective:
Destroy the three forts.
Eliminate the Anti-Richthofen Squad.
Time: 9:30

The first actually difficult mission in the campaign. There are four objectives which each require an entirely different approach, and need switching from one side to the other constantly.
First, the eastern fort can be destroyed with only your starting units, as the AI barely bothers defending it. My spotter balloon sets up line of sight for my artillery to safely take out the towers, after which everyone moves in to efficiently kill all the buildings.
Second, the artillery spotter balloon can singlehandedly destroy one of the forts, so I obviously choose the one furthest away from me.

Third, the western fort is assaulted with an army of Howitzers. This fort is heavily defended, in a manner that is completely random. There could be tanks here. There could be infantry here. There are always a bunch of artillery in widely differing positions. And worst is, howitzers are horrible to micro because they move slow, accelerate slow, their turn rate is attrocious, and they tend to stumble over one another. In order to alleviate some of the randomness, I put houses and towers around the siege factories, which will prevent artillery units from spawning out of those buildings, but it can only help so much. It takes extreme luck to even enter the fort unharmed, and succesfully destroying every building at a good speed barely ever happens.

Finally, once the forts are destroyed, a squad of fighter planes spawn in the upper right corner that need to be destroyed. Since waiting for them to fly to your base is slow, I sneak my civilians into that corner to build an airfield, allowing me to keep a flock of planes very close to the spawn location for a speedy kill.
There's definitely some optimization possible here, but it'd just require even more blind luck.

4. The Somme
Objective:
Destroy the capitols at Peronne, Roye and Montdidier.
Build a barracks on the capitol sites.
Time: 17:35

For once, I don't have to abuse the free resources glitch, as the game offers me nigh infinite amounts anyway. You're supposed to build up an army here, while random soldiers from the west side try to scout you out, but somehow the devs forgot you can build transports over the river and completely avoid the detection triggers that way. I still have to stay undetected and below 100 supply to keep my resources, and also to keep the Blue player inactive all game long, but that's no big deal... usually.

Destroying Peronne is simplicity itself. Getting rid of the airfield allows me to use this area as a forward base, from which I can set up assaults on the other two cities.
Roye has a bunch more defense, so it requires a bit of preparation. Destroying the artillery on the mountain is vital to keeping my army healthy at the chokepoint, and from there tanks and howitzers do all the work with ease.
Lastly, Montdidier is the best defended, mostly because its planes and units actually start attacking you while you're still approaching. The army, as big as it is, is therefore a suboptimal approach; instead, I just bomb the place and sneak my civilians into the city.

It's vital that I build the barracks in this order (Montdidier, then Peronne, then Roye), because the Montidier barracks is the riskiest to build, while finishing Peronne's barracks causes a bunch of unit spawns that would destroy the Montdidier barracks pretty quickly.
What makes this mission by far the worst out of the entire campaign is the sheer amount of things that can go wrong. Accidentally hitting 100 supply or getting discovered activates the blue player, who will kill my civilians. Random fighter planes or bombers can kill my civilians (as they almost did). They can also kill the howitzer whose task it is to destroy the artillery, which can make conquering Roye impossible. And that's just the RNG, there's plenty of room for me to screw something up as well.

5. Lightning Warfare
Objective:
Destroy the capitols of Poland, Scandinavia, and France.
Build town centers on the capitol sites.
Time: 11:45

This mission, like the previous one, expects you to build up an army in your base before setting out to conquer everything. And again, the devs forgot water is a thing. I'm sure the Allies don't mind me positioning units by their capitols, right?

To make sure that I'm actually able to destroy the capitols and keep my civilians safe, I abuse a really silly oversight: attack ground on top of "enemy" units kills them without being at war with them. Sadly the structures are triggered to heal on any damage taken, so I will eventually have to declare war, but I can do so when everything is as safe as possible.

Problem is, AI is random. The two major runkillers are the Polish tank army, which just drives around randomly and can take far too long to destroy, and France, which can either instantly overrun my units, or ignore them completely. Protective structures can help and/or distract, but success is very random.

6. Preparations for Invasion
Objective:
Destroy all of Britain's docks.
Destroy the British Home Fleet.
Time: 13:03

The only mission in the campaign where I truly abuse the hell out of the resource glitch. The Home Fleet is a pretty significant force, so to get rid of it as speedily as possible I'm gonna need a lot of units, fast. Since the game starts me off with 4 naval yards, u-boats are the obvious choice, and they're furthermore optimal for being small (thus allowing better concaving) and immune to battleships and carriers.

While those guys are building, I start getting rid of a few docks on the north end with some battleships, and build up an airforce to deal with the last remaining docks. Here the mission's RNG shines: Britain will construct battleships whenever it can, but where those things end up, how many they'll be able to get, and how annoyingly positioned they are, is all random. Furthermore, whenever a convoy reaches Britain, they're able to build docks manually, which they can do literally anywhere on the island, forcing me to keep every edge covered so they don't sneak one past me.

This is one of those missions that could be infinitely optimized, but this is the only attempt where I've managed to clear every dock before destroying the home fleet, without any complications or major errors, so I'm fine with it.

7. Operation "Sea Lion"
Objective:
Destroy Buckingham Palace.
Build a Town Center in place of Buckingham Palace.
Time: 3:42

A surprisingly easy mission, everything considered. There's nothing preventing you from sending a group of bombers directly to Buckingham Palace and immediately destroying it. A transport filled with civilians has to manouver past a bunch of sea mines, but that's no big issue. And the trigger area for what counts as Buckingham Palace is so big, putting a town center outside the walls still touches the triggers and counts for victory. Kind of a shame that this mission is so simplistic when speedrun, but hey, gotta go fast.

Total game time: 86:58.

All in all, this campaign was a lot more difficult to execute than the Russian campaign. After the first two missions, several hours of grinding were necessary to bring the runs anywhere close to optimized, using the riskiest strats I could think of. The amount of time I'd need to put in just to shave a few more seconds off some of these missions is hardly worth the effort when there's no competition in running this game.