You're ordering 3 meals for 2A and 2C. Sounds like 1.5 A credits and 1.5 C credits. It's likely the adults will be eating more than the kids, maybe the kids will be sharing one meal. Who is to say the "correct CS credits" isn't 2A and 1C.
That said the CM will probably go along with the 2A1C request. It's certainly possibly your kids will each be eating a meal and you and your spouse will be splitting a meal....this point may not apply to you....... but if too many greedy guests decide to use their child credits at Pizza Planet but none of their adult credits Disney will just put in a kids menu. That would be a lot easier than just saying the first 2 meals ordered will be charged as adult, the second and third could be Child.
The fact that Disney is allowing
kids to order off the adult menu doesn't mean that Disney intends adults to be eating meals bought with child credits.
My guess is we'll be seeing kids menus sooner rather than later.