Re: fatigue of reinforcements, perhaps they just modelled very simply, the fact that all units (on the map) get tired to two bars after sitting around a long time. IOW they simplified by assuming you wouldn't need reinforcements until after a while, and just made all reinforcements be two bars, period. That's the bad news (if you need a reinforcement early). The good news is that somebody pooped past two bars, can always get back to two bars, if they can rest a while.

This doesn't apply to extreme hot or cold, where armored units will tire much faster. But on a non-extreme map, all reinforcements have been two bars, and all on-map units can rest back to two bars, in my experience. But I very rarely call for more guys early.