As a matter of policy, I just don’t keep QBs if there are other options cause the class is just way to deep. The point differential between Wentz and whatever QB you can draft in the 9-12 rounds is much smaller than the point differential of Ajayi vs whatever RB you can get in those rounds. And this is coming from someone who doesn’t even like Ajayi as a talent but the opportunity is hard to ignore. Also, Wentz is still recovering from his knee injury so not a lock that he’s there to start early on so you’ll have to roster 2 QBs.
And the other issue with your approach of focusing on WRs/RBs is that other teams will also be keeping 3 players. And given most people apply the don’t keep a QB approach, or at least they should, that is another 33 RBs/WRs off the board. So even if you can focus your draft on them, who knows what slim pickings will be left. Always a challenge with Keepers but if possible, should try and project what other guys would keep.