It also helps to build up a variety of team players for your future endeavors by checking out the company page here on Bigger Pockets to hook up with a few professionals in the area you need team support in.

In that time I've met more real estate investors than I can count, from single family to commercial, both small scale players and mega investors. 

I realize you can get infinite ROI with BRRRR, but I don't think that's what the big players do.

Are these still the main players and if so, who would you recommend?

These company owners likely know what players would be interested in having a look.  

Has anyone been working for one of the large players and switched to KWC?

dont really knowand Blazers affect the real estate market like 0 %  .. other than the few players that buy maybe 5 or 6 multi million dollar homes.. 

When I say "big builders" I don't mean the publics--I mean the local guys who were the dominant players in the market either pre fire, or pre-market-collapse that have come out of retirement. 

Keep in mind that many markets have players you don't see.PE/HFs/Institutional Money is investing in a core asset base. 

(Even though it is definitely possible) The best thing is to educate, save, and also reach out to people in your target market so you can get your name out there and learn who the players are.