[rdonj]

Well, it's fairly easy to make a unit that turns into lesser versions of itself. That you can do just with setting #secondshapes. If you give one of the loss stages a #firstshape it will change to that shape after the battle. I don't think you can heal it in battle and have it assume the #firstshape but I could be wrong. In that case it would probably be better to give both temporary forms an initial form of the fully intact howitzer, I am not sure it would work correctly otherwise. Another thing you could do is give the howitzers #secondshapes and #shapechange. It wouldn't really help them in a battle, but you could bring them back to full on the strategic map.