The bolt will also release from the crossbow more quickly than an arrow from a bow will, but the reload time will be longer for the crossbow to begin with. A bolt from a crossbow will more easily penetrate heavy armour than an arrow from a bow will. The most significant advantage of a crossbow over a bow is perhaps the more powerful impact of bolts.
The main differences between an archer and a crossbow build come in the form of projectile type, the speed of the weapon (both in firing and reloading), aim gauging, and of course the perk tree. As with an archer build, choosing a crossbow as your main weapon in Bannerlord is entirely viable.