My personal opinion is that the Chiefs shouldn't shoot for a SAM LB unless they can't get an A-level WILL. I just don't think, with his reliability thus far, that I like all the eggs in the Gay basket there.
Gay can play either SAM or WILL, which is valuable. The more important in today's NFL though is a good WILL. You need that fast coverage guy. They put in Niemann so much because he's "relatively" adept at coverage. He's not good enough though. He's especially not fast enough to be where you want as a defense. You give me a guy like Dean or Clark out there every down with Gay playing on the strong side and I'm a happy guy. Something happens to your weak side guy, you still can move Gay over. That, and I'm not necessarily on the let Niemann walk train. He's not great, but he's good enough to keep around as that 4th or 5th LB.
I think if you go for a more traditional SAM, that takes away some flexibility. You don't want a downhill guy like Denzel Perryman. You want a guy that can play multiple looks as Gay can, and I think unleashing Gay with a blitz from the SAM is a great way to use his skill set. I think Gay being in the SAM lets you cover well from that spot too without giving anything away. Give me a Deion Jones or De'Vondre Campbell type of player at the WILL that can cover and make plays in space. We have our downhill thumper in Bolton.
My hot take.
