Hello this is my first time posting here in this forum.
Why do some coffee beans need to be more finer than others to pull similar shot of espresso? (Time, yield)

I.e. sermon coffee by verve takes much more finer grind to pull the recommend shot. 1:1.5. 18g:27g:23-26s
FYI it was roasted 10 days ago Water temp; 92C/197.6F Environment temp;20C/68F

with this machine setting and the beans it takes lower than 2 clicks in the niche to pull a decent espresso. Anything higher than this would pull too fast. And this is very fine. I pull verve decaf beans (vancouver) with 6 clicks on the niche.

Any response about this issue would be greatly appreciated.