Well, AFAIK that isn't needed, at the start of the war you juts "deploy" your current troops, and as you get more you "deploy" them as well. Tough i could see something related to movimentation of troops working and adding to the game...maybe the GM will want to change that if he doesn't likes the old system
What I mean is, the UK has a huge fleet, and a large army as well. But, you can't necessarily just expect their entire fleet/army to be readily available all on Australia or some such when they control an entire world naval empire. There may be some reason for the UK to focus parts of their fleet in certain areas but I believe it wouldn't be wrong to perhaps have a "war order" stating, to station a certain amount of troops in a particular region, or to move their fleet to shore up the defenses of an area.
At least that's what I'd perceive. I mean if an empire with an army of 500k, always had 500k on whatever border they were fighting on they would be much stronger than an empire who had to spread that 500k across multiple fronts at once.