50 while never terribly complex never had "nursery rhyme" raps unless you count blatant money grabs like candy shop. He's much more of a song maker than a wordsmith though and has stayed pretty consistent with that style.
Cam on the other hand, in my opinion came out the pre-rocafella was easily one of the most top 5 underrated lyricists. As a big fan of his during the COC/COF/SDE era the nikka started sounding like Dr. Suess to ME. I didn't think it was a widely held opinion and didn't really care, but it seems like I wasn't the only one who noticed