I'd argue that English barons/earls were more comparable to CK counts/dukes respectively.Don't really get Paradox, barons are the major political players in many feudal kingdoms (*Cough* England *cough* No dukes till the end of the period *cough*). The whole 'aaah barons are irelevent you can now remove their titles with no fuss' Erm..... Ok, so I immagined all those historical rebelliosn where kings were toppled or nearly toppled beacuse they pissed off their barons a bit?
But one big aspect no one has mentioned with making barons more complicated, which I am sure had an impact: performance. Adding more fully characters doing things (plotting, interacting, etc.) is a hit on performance. Making barons have full-fledged courts and interactions would essentially triple the number of courts to be simulated, for little gain. There's a reason that many of the performance improvements in CK2 essentially required cutting baron courts, history, interactions, etc. to the bare minimum.