You fail to see the difference of a 4-4-2 and 4-3-1-2 CUG, besides the latter being in a completely dysfunctional form, its also one that didnt suit Momo and required more from hm as it was based around possession footie and him being more offensive. But 4-4-2 DM he is totally natural for, and he was a beast in under Ranieri, litterally fell apart without him when he got injured late years season (it was clear he was masking the teams and Ranieri's fragile state), wasnt no coincidence we started leaking like HELL then. Plus even if passing isnt his forte, he kept it simple and basic then, and didnt make miss passes nearly to the degree he did this season under Zaccheroni (I cant say Ciro as much, because he was injured all the time).
Basically as one of the 2 CMs/DMs Momo > Melo, Poulsen, and yes frigging Candreva too.