Sure you can deny it. You picked the classic example of something that seems hard to you because of your native speaker bias. What some languages resolve with conjugations and declensions, others resolve with combinations of prepositions and word order. English verb-preposition combinations are so brutally hard for foreign speakers to master that they publish "collocation dictionaries" to help. Latin's case system is much more predictable and regular, in some ways it's easier to learn.

Ranking human language complexity is a much more difficult task than you might imagine.