Notes from author
I decided to make a build that ONLY uses bows, a greatbow, and a crossbow.
I've tested it out and it's super fun.
The composite bow is for most encounters, it does good damage at short ranges, and most of your encounters will be at short range.
I added the longbow because it does more damage than Pharis' bow at long ranges, even though Pharis' bow is supposed to do more. This is because while Pharis' bow does have less damage drop at longer ranges, the longbow scales with STR and DEX, and does much more damage in the first place. I'd use this for fairly long range, but not too long.
That's where the greatbow comes in. For killing something that's out of range of the longbow.
I keep Avelyn in my left hand with my composite bow in the right most of the time. If the opportunity present itself, just give 'em a barrage of lightning destruction.
For testing ranges, I went to the undead parish where the armored tusk enemy is, just past dragon bridge, facing the tusk head on. I aimed at the undead soldier who pulls the lever when you get too close. He is outside of the range of the longbow, it's ranges like that when you need to use the greatbow. For the crossbowmen on the bridge above the tusk, the long bow did just fine.