Well if the flying AI is fixed moats and walls should be less important. I don't know about construction destroying but that would be great.
Anyway, think about what a basic military champion would look like converted into a standard creature. With a year of sparring thats legendary wrestler and moderate weapon, armor and shield skills and maybe 5 stat points in each stat. A set of Iron Plate armor with some quality would be about 10 damblock or so easily. The shield would block probably half of all attacks including potential criticals, I think the best way to represent that would be doubling the speed in addition to to the massive agility bonus. That means fastest creature in the game, by far. Legendary wrestling basically means [noexert], because anything else is going to get tired first. Also it gives a chance to dodge, stun, and throw the enemy onto the ground but I don't know how to represent that. I would say 5 toughness is closer to [nopain] then not having nopain, without it things break a foot and then fall unconcious and usually get killed immediately (thats kills tons of megabeasts in worldgen). Iron axe should be at least 1-11 slash damage. A quality or two would easily mean 15 max damage and I think combat skill would justify a much higher minimum damage, so maybe 5-15? Five Strength and Toughness would become 2 or 3 extra creature size, I think, so [size:9]. Military Dorf = King of Megabeasts even without steel or a masterwork clown suit.