Defense has picked up impressively. Aquirings of Holliday and Barber have turn out to be quite successful. Barber, in particular, played well all game last Monday. He was cut by the Redskins due to serious knee injury years ago and the team didn't think he was able to comae back to his top performance. He and LaVar were good buddy and prospect LBs tandem back then, and are still close friends now. He has proved that the Eagles made the wrong decision by not paying him mega bucks, (his contract worth about $30M in 6-year span, if I'm not mistaken).
I agree with K.เสือปลาขี้เมา that they didn't overpower the Raiders, divisional long time rivalry could be a good explanantion. They, however, were able to get the job done by distracting Gannon all night and finally knocked him out. Johnnie Morton has also stepped in and helped out the offense much better than last year, his first year as a Chief.
One thing they have and most teams don't, yep, Dante' Hall. Reliable PR/KR and K are a must for the new era NFL. Talents on offense and defense are very similar and will be even closer and closer. Hall alone can scare opponents' P and K and pressure them to kick the ball out of bound to avoid him. And most of the time, when you kick out of bound, the ball will be WAAAAAY too short than its supposed position. That gives Chiefs offense a very good field position to work on, just that simple.
Also, the offesive line is among the league's best. When you have a pocket passer behind your line, stable pass protection is mandatory (I hate to say this but look at the Redskins, they're killing their own future right now by let the opponents, yes, whoever, get into Ramsey's face with ease).
Holmes is on top of his carreer and might not last so long. They could win the division without much doubt. The schedule too favors them a lot. Two tough games down the road are against DEN and MIN. So, I'd say, they should be AFC #1 or #2 seed heading into the playoffs, regardless of injuries.