Hi,
sorry, I managed to overlook this.
A bit of history: CMPzC was started by he guy that goes by 'noob' on the BFC forum. He put a lot of work in it but is also a control freak. IIRC we started to campaign three times and every time he found some rule glitches and started it over.
At this point Fizou, Kuderian, another guy and myself split off and started a campaign in Sicily with the rules we had and solved things on the fly. That went without problems.
I can not say much about the workload involved to transfer unit data between CM and PzC since I only played the CM side. AFAIK most problems come from mapping unit sizes and getting the headcount right. Then you have to make a map of course.
Setting up the scenario would either require a referee or some trust not to look into the others setup. We went with the latter.
Problems:
- retreats: in CM it's easy to leave the map without losses. So you could run away for ever without punishment. So we put in some rules that you take a morale hit if you leave too early.
- when not to play CM: some setups are too unbalanced to be fun but others are. Discerning those is difficult.
- realism vs playability: this is an ever ongoing debate and is a matter of personal preference. It should be clear from the start to which camp you belong to avoid conflicts later.