I use a scale of 0-5 typically. Sometime if i have an ELITE scorer ill put his distro at 6.
I like to have a distributing PG that i usually run at 0 or 1. He will get touches because hes the PG but will pass more than shoot.
Then i like to have at least 2 scorers in my starting lineup at 4 or 5. My secondary scorers i put at 2-3.
I also like to have a bench scorer that i run at 4-5. Typically everyone else gets a 1-2 depending on their IQ and attributes.
This will allow for a consistent play IMO