The Bills are deeply flawed.
They essentially have a runner for a QB who seldom throws to a WR. Watch him. He has very poor fundamentals and doesn't seem to have a good sense for when he needs to get rid of the ball. Not particularly accurate; inconsistent.
They are actually very one dimensional offensively.
Their defense is middle of the pack, and pass defense is in the bottom third league wide.
The Bills, to me, are pretenders.
The Rams, to this point, are true contenders (didn't think I'd being saying that this year).
They are ranked in the top third and higher in all three phases of the game. They can run, they can pass, they can defend the run, defend the pass and have very good STs. Goff is a true NFL QB with good fundamentals. The Rams might have the best punt/kick duo in the NFL. Pharoah Cooper is near the top in KO returns.
I don't see any major flaws in the Rams.