No contest in the paternity department.....
Well, with all those kids workin' away copying out the parts for this and that, and finishing things off for him, no wonder he was able to be so prolific
You can just picture the family scene at suppertime, with JC saying to CPE... "Here, can you polish the rest off for me? In G minor in 12/8, with a modulation into the relative major at Bar 32, an interrupted cadence at Bar 48, finishing in the tonic at Bar 60. In the style of JS Bach. If you do it before lunchtime, you can go out play Sturm & Drang with Stamitz in the afternoon."