It will be pretty well to move military unit between military buildings.
Don't be sucks - settlers 2 was released many years ago, you could do Widelands better.
I imagine this in this way: 1. User click on military unit and go to transfer page/click on transfer button 2. Window similar to attack window would appear 3. User selects how many units may transfer That all!
Additionally, it could be fine to extend attack algorithm to selects range of unit used in attack. I think, there will be also great to select from how far destination units will went.
It could be also possible to selecting flags too. Why flag couldn't be less military building, without zone control?
Sorry for my English and words - I still learning.