Yes
The probability of winning the event very likely does not strictly increase as your rank improves. There is very likely a “serpentine valley” of sorts where teams are more likely to win the event if they either seed better or worse. My rough guess is that this valley is centered at about rank 10 based on this graph: 
Relevant post: paper: Miscellaneous Statistics Projects - #26 by Caleb_Sykes
If getting 4 RP will put you at about rank 10, it’s probably in your best interest to get 3 RP instead. Someday I’ll do a more thorough analysis as the above one is pretty crude, but I’m moderately sure event win probability does not strictly increase with increasing rank.