Free Agency is for lower tier players and vets who are beginning to age out. Bills resigned Shakir, Roussou, Bernard Gilliam, Ferguson Hamlin, and Allen (again) this offseason. Oliver, Milano, Dion, Brown, Epanesa, and Knox all somewhat recently signed second deals with the team. If you’re doing it right you draft, develop and resign your own players. It doesn’t always work out but the core of this team is made up of draft picks or UDFAs by McDermott and Beane.
Rapp, Douglas, Jones were the 3 starters on Defense who were not drafted by the Bills.
Edwards, McGovern, Cooper, and Hollins were the 4 on offense. Certainly other FA signings play but the core are all Bills UDFAs or draft picks.
Even Bass was a draft pick and Ferguson was a Bills UDFA.