Interesting note on 2013 Topps Minis

CWC

So I've opened 10 boxes so far and while I have 5-7 of most base cards, I only got one Manny Machado and one Mariano Rivera.
Is this just bad collating or does Topps produce certain cards in lower quantity than the others?

3BoyzTrading

Welcome to the boards, the mini's are notorious for bad collation.