I'm sorry by in the GD, while they didn't use points, they certainly did nod to each other or communicate where or who or what. It's not a permission thing, it's a feel thing. And usually the osngs were pretty set in stone so there was almost always specific places where the solo occurred. The only real change up was how many times they'd do the bars (ie if jerry had a lot to say or maybe felt his solo didn't say enough, or felt "that was ll that was needed").
So I think your cirticism of John, that they need a guitarist with more confidence, is completely off the mark. Any guitar player in furthur will have to expect to know his solo, how many bars said solo should be, or if he wants more or less, to look at Phil or Bob and give a "is it ok if I....." look and see what they want. It's Bob/Phil's band. To think otherwise, to me, is simpy wrong.
This aint the dead. It's Phil Lesh and Bob Weir's band, Furthur.