My Criteria would be this (just throwing something out there for fun)
-If you have 15+ career wins (Combined "Official" PGA and European Tour events), you must also have at least 2 majors to be inducted into the hall of fame **if you have 2 majors and less than 15 Official PGA and European Tour wins, too bad.
-If you have 0 majors, you must have at least 20+ wins (Combined "Official" PGA and European Tour events) to be "considered" into the hall of fame. A confirmed induction would be at the discretion of other credentials i.e. Ryder / President Cup appearances, OWGR, number of wins over 20 (say you have 35 wins), etc etc...
**Note - if you have 20+ wins and 1 major, the 1 major barely kicks you in without the credentials.
A good example of someone besides Fred Couples who would get left out based on this criteria is Jim Furyk. He has 16 Official PGA Tour wins (0 European tour Wins) and 1 Major.
Another good example is John Daly. He has 8 combined European Tour and PGA Tour wins along with 2 majors which doesn't meet my criteria.
I would induct Colin Montgomerie as he has 31 Official European Tour Wins (0 PGA Tour) and 0 majors. However, the extra criteria that gets him in is the multiple European Tour order of merit awards, OWGR status during his career and Ryder cup playing / captain experience.