I look at this Chiefs team and I think the core is Mahomes/Hill/Kelce. Those are the guys that can lead them to the promised land. So look at their contracts.
So Hill is signed through 2019 and will be 25 when that contract ends. He's on an ultra-team friendly contract, as is Mahomes
https://overthecap.com/player/tyreek-hill/4878
Mahomes is on through 2020, again with a very team friendly deal.
Kelce is signed through 2021, at which point he is 32 years old. The deal isn't stunning team friendly, but it's perfectly fine with cap charges that never exceed $10.5 million.
https://overthecap.com/player/tyreek-hill/4878
I think you can pay both Mahomes and Hill near/at top of the contract range and keep Kelce. Hunt you have to let go if he's looking for stupid money (and of course he will be). RBs are fungible.
Houston is 29 now, and his contract runs through 2020 with cap charges at $20MM. 31 isn't too old for a defender, but I doubt you extend past the current contract at those numbers. He's not Donald or anything.
Even under the Patriots system, you pay the guys that are serious difference-makers -- that win you championships. You can plug and play alot of guys, but the guys who are potential first ballot HOFers, you can't replace.