[Mobhack]

Expanding the core is a given. As will be cross attachment.

I can't think of any reason to stick to the same core you start with. That really only happened in SP1, where no addition or cross attaching could be done, only changes of unit type. So in SP1 you would start a campaign and ensure your full 48(? may have been 24) allotment was filled - even if it was jeeps or sniper placeholders (SP1 charged 1 whole point for a sniper, so they were extremely good value).