Zeke or Mixon ROS PPR?

I’m looking to leverage the bye week to buy either at a discount from one of my leaguemates who has a rough record. I am currently 4-3 and have an opportunity to push the 2nd most well constructed team(behind mine ofc :wink: ) down to 3-5 with a win this week(giving me pause to trade for Zeke). Am I putting too much emphasis on playoff positioning over buying a player who gives me the best chance at a championship?
Also my matchup this week could go either way based on projections.

Bump, help pls