The staring german army is seems to be lacking the Garde-Ersatz-Division and 3. Garde-Infanterie-Division, the 1 & 2 Garde-Reserve-Division are not Guard divisions as all of these 3 division should be, secondly Germany is unable to build more Guard divisions, while historically they raised the 4. Garde-Infanterie-Division in may 1915 and 5. Garde-Infanterie-Division in January 1917.
Secondly Guard and Alpine division do not seem to upgrade like normal infantry division. In most WW1 army's, these units were elites and thus got were prioritizes for receiving new equipment, it thus seems weird that they in game should not be able to received metal helmets, new tactics and flamethrower and the other abstracted benefits that the infantry upgrades are supposed to model as i understand it.
The size of the starting merchant navys seems a bit off, in otl the german was about a fifth the size of the British, at 4.4 Million BRT second only to Britain’s 20.8 Million BRT (The Austro-Hungarian Empire’s merchant fleet stood at
about one Million BRT, Russia, Italy, Japan and France - the other Allies - had merchant fleets
totaling about 6.4M BRT, France about a tenth of the Brithis, Italy and Japan had about the same size, and russia half of those to again) World merchant tonnage in the summer of 1914 was around 42.4 Million BRT, UK about 50%, FR 5%, IT and JAP 4% each, Russia 2% DE 10% and AH 2%, US 6%, NO 4%, NL 3% and SV 2%. The loss of the merchant navy was a major blow, so this should be modeled as something to do in the early naval part of the game imho. Again, i do understand if it is hard to get the AI to hunt CP merchant ships, but if they could have sailed longer the resource situation could have helped germany in the war.
Also if germany does not invande the Belgium and or Luxemburg, i think it should take longer to get the UK into the WE, historically the British goverment nearly fell over going to war with the invasion, in a scenario were this does not happen it should take longer that it currently does. I do understand that this is a balance issue thought.
Lastly, Georg Bruchmüller should have some sort of Artillery ability modeled in game.