Slitherine

It seems to me that if you start as Colonel or higher there is not enough points to start the campaign, what additional points you earn are used to heal your existing units and limits what new ones you can purchase. This only gets worse as you progress and limits how far you can play. If you play below level of Colonel the AI is much easier and is not as enjoyable.

Ideally, you want to be able to have your units progess so you can increase their unit strenght. Again, with the limited points and if you need to replenish them at the beginning of a new campaign then you have a lot of slots open that cannot be used due to limited points you get.

I thought this at first also, but after restarting the campaign this is not a problem. Just remember, that don't get your planes reduced just to try and get some experience like PG/PG2. And upgrading equipment is not that bad. Also setup your attacks with artillery and Level Bombers, to suppress the enemy, so you take less casualties.