The point is that you'd expect the agent fee to be relatively proportional to the total transfer fee, which would make those above percentages comparable. Chelsea bought Caicedo for €116M and Lavia for €62M, so I'd expect Lavia's agent fees to be approximately half of Caicedo's. Obviously we don't know the exact details, but when we're talking about agent fees across Liverpool's 4 signings and Chelsea's 11 signings, I think its a pretty reasonable assumption that they're relatively proportional.
And Chelsea don't have a bunch of "lower market" signings - 8 out of 11 of them were higher fees than what Liverpool paid for Endo (€20M).
- Liverpool bought 4 players for €172M (€43.0M per player).
- Chelsea bought 11 players for €468M (€42.5M per player).