When it comes to stuff like this I always trust Vegas oddsmakers, they look at more than just results unlike ESPN and many others. MGM currently has the Bills as pretty big SB favs. The Eagles are 2nd, Chiefs 3rd.
After the Fish game, ESPN had the Minnows #1 in their power rankings, but MGM had them #9 in SB odds because unlike the talking heads, the oddsmakers looked at the entire situation (our entire secondary out, several other injuries before and then during the game, the excessive heat, etc).