I think the safeties are only responsible for covering the depth in your play call (Short/Medium/Long), and the LBs handle the RBs and TEs. I'm not sure how exploitable this is from Trips since you only have two receivers against roughly two coverage LBs. It might be a good matchup against Dime. As far as attributes, definitely look for low formation IQ. Speed, GI, Tech, and Athleticism probably play a small role as well.