For high speed / RF, you want many narrow fingers to hold
down Rg. For analog you want wider, as much mismatch (esp
at weak inversion) can come from the channel edge (bird's
beak) or strain effects (STI). Your foundry may or may not
break down mismatch into area, w, l dependencies (often
only area is discussed; whether this is because the others
don't matter, you would like to know). You could deduce this
from looking at MM-vs-area plots' detail, whether narrow*long
and wide*short occupy different points on the map for same
area.
I don't think there's value in assigning all devices the same
finger width, in analog. Outside of a must-match group, at
least.