Can anyone tell me why my level 40 engineer provides 76 points towards garrisoning while my level 60 marksman only provides 61?
Yup, the higher your number will depend not just on its level, but how much you have put into sacrifices long level up your heroes abilities. They don't have to be lv2 (confirmed, I have 2 heroes that are 1/2 way upgraded to lv2 and I still have double the points than ones the same level with no sacrifices at all).
the talent does not affect your garrisoning ability. (thank god, because it would be super expensive to refresh talent til 5/5)