so imo shotguns are not overpowered, high impact shotguns (felwinters, matardor, party crasher) however are overpowered. removing shot package completely hurts every other shotgun and will do little to the worst offenders.
go play PvP with something lik the "Patch-A" or "the next big thing" (next impact tier down from felwinters archtype) and they arent nearly as effective as thier higher impact cousins. they require a melee finish at the range a felwinter will just destroy you at.
i believe this what bungie wanted out of shotguns so why not just remove high impact shotguns and leave shot package alone.
remember that all shotguns can achieve max range stat but only the high impacts can hold that damage at those ridiculas ranges.