I think the shotguns and bolter need some new patterns because the shotguns (even with decent blessings and rolls) are lacking in the damage department. Like a new pattern of shotgun that specializes in huge boss/ogryn damage like the triple barrel lathe pattern boarding gun for example. Small mag Capacity, slow with massive recoil but does insane point blank damage to big boys and horde clear.
As for the the bolter, a bolt pistol would be cool especially with the “commissar” builds and cosmetics. High crit chance, low magazine for people to have another hand cannon in the game.
I do think that adding more than 3 variant can be good things, for certain weapons, mostly those where the variants aren’t simply Heavy/Medium/Light but instead offer new gameplay variation
New Bolter variants like maybe a weaker on with higher rate of fire, a piercing high damage but only single shot variant. But I feel like a completely new “heavy” shotgun would be an excellent addition to zealots and vets