I use to consider this a minor bug, but I have found it can alter the game quite a bit.

First problem: we can't view the stats of an army inside a barracks or a tower.

Second problem: we can't switch a units mode while inside a tower or barracks.

These problems have work arounds but they require your units to spend more MP and BP than they would have to normally.

Currently you have to move the army in question out of the building to do what you want with it, or at least have one unit outside of the building if you are transferring troops. When you want to change the mode of a unit, you have to move it out of the building, which cost MP & BP, change the mode which cost 50 BP then put it back in the building, which cost more MP & BP.

I had a unit at 145% BP and full movement in a barracks. To switch it over to defence it cost me 125 of my 145% BP and 9 of my 10 MP. It should have only costed 50 BP. Instead I have a unit that can do nothing for almost a full turn, when it should be able to fight if necessary. I think this is a very expensive payment just to have troops in buildings use defence mode.

So this bug has the potential to drastically alter the game by preventing players doing what they need to.