yes, tested that too, its true.
shouldnt be really, as different units carry different stuff, and/or move around more in general...i mean afterall an armoured horse should tire a little faster than a light one, even when it cant run quite as fast...or when having to drag a heavy chariot, as oppossed to a light one, and better training or experience doesnt affect stamina...the recovery aspect is still great though...as i dont really mind having to fight longer battles, so having a few very hardy units who can rest up faster and attack the enemy who is still catching their breath is useful...not as many losses, well not for your army anyway.