I know nothing of AH, but the principle goal of Germany was to prevent the squeeze of Russia, France and Germany at Sea.
So, they go to war in a kind of aggressive self-defense (which is obviously not very peacefull). Accordingly, the objective after a Victory would be to fight the next war on
safer terms. Probably would need to take some of Frances mining and industrial regions closest to the border or get some disarmament concessions.
With Russia, the baltic states as German puppet kingdoms was mentioned "to cover the left flank in the NeXT war". That logic is the same here.
Now, this might not have been realized when the war started, but this is something they could have come up with if asked for terms.