Since battle medics are a part of TF2, they should be good for Saxton. It's just that Medics are known to leach off damage (healing an engie or heavy) that's the only damage they do. Although there is the Crusaders Crossbow with crits, it doesn't seem to be the weapon that can get the job done. Or where a large amount of people use it. Instead I suggest putting mini-crits on the Syringe Gun. It's not to overpowered nor to weak. A nice balance where you can shoot, get uber, and deal a decent amount a damage all at once. All in all, this would make medics more useful other than always having to be with an engie or heavy for dealing damage.