[Suhiir]

I'm doing something similar with my 13th MEU campaign.

First you need to buy ALL the core units needed for the player side, each and every one to be used at any point in the entire campaign. Auxillery units that are only in a single scenario aren't a problem.

Each scenario you can set any core units not used for that particular scenario to reinforce turn 50, just insure your scenario is 49 turns or less long. That way a tank destroyed in scenario #1 but not used in scenario #2 is still destroyed in scenario #3 where it may have been used.

As to the AI ... just buy those as needed scenario by scenario, remember they are lemmings, so most won't survive from scenario to scenario.