In my 2.5 campaign play-through, my first two harvesters had only 4 aliens. Even a landed one had only four (even though it should have the full crew). A harvester attacking my base had 6 aliens. Later in the game, fighters routinely have 7 or 8 aliens.

This isn't consistent with the crew size specified in the UFO script definitions, so I suspect there is something internal that is effecting the alien team size, to make early crews smaller. If so, this should be removed.

But alien team size definitions will probably need to be adjusted when this is fixed.