I do practice and shoot as well as you, would only need 1-2 rounds per assailant. How many assailants is always an open question.
Illegal alien MS-13 travel in packs, 6-8 is typical.
MS-13 type gangs have no record of invading indigenous American citizens in large numbers. They mostly prey on immigrants from their country of origin. Also, the Trump Admin is doing a much better job of dealing with MS-13 gangs.