How compatible are the two games army lists?
Can I take (e.g.) a modern US army list from CWC and an invading alien force from FWC and pit them against each other using the FWC rules? Or would the CWC list need tweaking?
I'm thinking along the lines of Spielberg's War of the Worlds or Battlefield L.A.?
That's an interesting question.
In theory yes.
Unlike the shift between BKC & CWC which is problematic, CWC to FWC is less so because the FWC weapon stats are more abstract and more governed by the use of the weapons upgrades & tech upgrades.
A 'modern' US Gulf War CWC list would probably be over powerful against an invading alien force, using FWC, but films such as Battleship or Battle Los Angelese (for example) should act as good reference points.
I'd make all the infantry small arms INF:LI/SF/ENG/SI/RECCE into * weapons (only inflicting suppression on armoured targets @ -5pts) but a lot of the FWC mechanisms - such as drones & target designators will work pretty well.
I'd be interested to hear how you get on.
Cheers
Mark