Turn off all the perk nodes, other than damage type, for weapons in PvP mode. Make it so each weapon behaves as if it's a starter white/common weapon, with only the base damage type (kinetic, arc, etc...), and no other perk nodes or hidden/innate abilities (other than auto fire for auto rifles, of course). For special events like Iron Banner, or other unbalanced play modes, the weapon's Attack/Light score would come into play. After all, PvP is supposed to be about SKILL, and not which player is bringing the biggest crutch with the best godroll perks, right?