What Matchmaking Should Be
It should not be pip-based.
It should be:
Your miss/good/great skillcheck ratio averaged out
Your Escape/Death ratio averaged out
Killers: (This is per Killer, not per account. Though your overall should be taken into account when playing a new Killer, so you don't face high skill Survivors as a new Killer, but you also don't newb-stomp)
Your hit/miss ratio averaged out
Your Kills per match % (0/25/50/75/100) averaged out
These should make up a skill number, and those skill numbers should be grouped together.