There is already a game on the market that has a turn based campaign move intergrated with real-time 3d battles. Okay it is not WWII, but feudal Japan - Shogun Total War -However, it does show it can be done and I have read they are planning further game releases.
I also agree that CM does lack a campaign element. Ok the individual games and operations are fun, but they lack any greater goal or sense of achievement. That is where projects such as CMMC and CMRPG come into play and hopefully we will see alot more of these cropping up.
Strictly speaking operations cater for large battles that last for 2+ hours. Okay you say it was common place for battles to last all day, but these would be broken up by periods of inactivity lasting half an hour or so, when troops on both sides would look after wounded, re-supply ammo and repair tanks. Hey presto An Operation.
Pucker