1. Billmen have pikes in their weapon spawnlist which is not good by the time the player gets to fight them, and isn’t good period compared to the swiss army knife that is the Billhook and the armor destroyer that is the polehammer.
2. Arbelasters are far more likely to spawn with a regular crossbow than a heavy one
Having the buffed arbelaster only spawn in patrols and events whilst the current one (which doesn’t have a heavy crossbow often, but still does have it) guard supply caravans would prevent the player from farming heavy crossbows too easily if they start as northen raiders, deserters or just anger a house.
When the holy war comes around the northeners get utterly stomped in any combat the player participates in, partially due to gunners. Having the northeners get some sort of holy fervor buff to resolve and equipment adjustments would at least somewhat make up for that.