it tends to got with tyre clearance. if like the grizl the approved tyres are 47-622 (700c) or 52-584 (650b) or greated, them it will be orientated towards the rougher side.
gearing seems to be usual 1x11 using 42x11-42 and the rougher side sometime come with 40 or 38 x 11-42.
Rougher is usually hydro brake.
As above, Sram works (that what I have on the gavel) but I prefer shimano and the shimano maintenances is easier (I don't need to work much on my shimano geared bike or my kids shimano bike).