Re: fingers - yes, they are a part of the tone equation:
Ears, head, heart and vision to fingers to fingerboard, pickups, cord, amp and cab to PA / room or to preferred method of recording.
IMO, all great players have a very clear vision of how they want to sound and they manipulate the gear they use (or are forced to use) to achieve it.
That having been said, Phil's tone was entirely different in the early days of the Dead when he used a Fender Precision through Fender amps, as was Jack's tone with his Jazz Bass prior to discovering the Versatone amp.
And - I believe we could all agree that both of them achieved their most distinctive and arguably best tones after interacting with the wizards of Alembic.
Why?
Did the excitement of finding a piece of gear that allowed them to hear the tone that that was in their head(s) spur a sudden burst of creativity or did it just allow them to feel more confident that they were doing what they THOUGHT they were doing?
For me, if my ears are telling me that something doesn't sound good, my fingers are going to hesitate to execute what's in my head / heart and creativity takes a back seat to frustration.