The reason he's spending in free agency is because he got Brady, Antonio Brown and Stephen Gostkowski's money off the dead money list. When you know you're going into free agency with around $65 million in cap room, you know you can target particular players.
What I like is what
@p8ryts posted above. Belichick is resigning his own players, recent Patriots, and good veterans in their mid- to late-20s that fit with the guys under contract. Between the return of opt-outs, especially Hightower and Danny Vitale, and the return of Trent Brown, Van Noye, Bolden, and Wise, the Patriots have a more veteran team that knows the playbook and the approach to practice and game prep.
I don't know all signees that well, but I don't see any knuckleheads like Antonio Brown who create distractions that this team doesn't need.