Ax, there is no such thing as overkill when it comes to subwoofers, the more placed correctly in a room, the better the FR across all seats. Overkill as in budget, that is a different story. I have 3 subs.

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85