Serus
Arcane
The main issue with KotC that many people had, myself included, was lack of choices when it comes to classes. Also, less replayability because of it.KOTC1 is one of the greatest RPGs ever and it only has three available classes for a party of four. KOTC2, despite expanding on both of those aspects felt unsatisfying in comparison.
Dark Sun SL is also an adventure for four characters and a top tier classic.
Party size is irrelevant, what makes or breaks an rpg is having great adventure modules.
KotC 1 vs 2 is just your opinion. The 2nd, feel or no feel - had more complex combat encounters - even if as a whole was in some ways worse. Party size is very relevant, objectively.