Theory 1:
The best salespeople naturally identify good fits for themselves so that they can thrive. We could guess that elite salespeople seek out the greatest selling challenges - something beyond their comfort zone - but perhaps they are simply too smart to sabotage themselves.
Theory 2:
The worst salespeople don't pay any attention to fit because to them, selling is just spouting off features and benefits, doing demos, generating quotes and proposals, and taking orders. Maybe they simply gravitate to wherever they are wanted?
Theory 3:
The best sales leaders, in hiring only the best salespeople, are rewarded with salespeople that can handle their selling environment. It's worth noting that the best sales leaders hire salespeople who are more talented than they are while average and weak sales leaders hire salespeople who are weaker than they are.
I haven't written about compatibility before but it's worth spending a few minutes to understand the role it plays in sales success and consider its value in line with Sales Percentile?