"lack of reps" is not why that pass just went behind Brimah's ear.
You're wrong about this.
Practice turns thought into instinct. When 4 out of 5 of the players on the floor have to think before doing anything, it's inevitable lots of mistakes will be made, some of them silly.
With enough practice together, players naturally become more confident in what they're doing together, and the mistakes start to disappear.
It takes some teams longer than others to gel, but unless you're bringing in multiple future lottery pick recruits every year, you're going to have to build a team the old fashioned way.
We're talking' bout practice.