[Hugh Manatee]

I think the units fatigue should factor into their trampling immunity if they do in fact get it. A unit that's to tied wouldn't be able to fly away fast enough(I see dead flat grackles in the road often enough to support that).

Tired Flyers should also drop like rocks if they try and move, or take damage on landing like the choppers from sid meier's alpha centauri(they run low on fuel and land outside a base or air field they take damage)