The way I see it, if you take Aldon Smith out of the 49ers D, they'd still be a top D. If you took Von out of our D, we'd struggle majorly. As for Watt, I haven't watched many Texans games. Only the one against us. And I'm unsure about his impact on their D as a whole.
I like how the top 3 defensive players are all 2nd year players.