Bills winning would be best. That would give them the same conference records for that tie breaker. I'm a little fuzzy on one of the aspects of the head to head tie breaker which is next but I think the Texans still win it. I'm not 100% on that though. A Buffalo win is needed though to even get it in play.
What we need is for Houston to lose first round with Bills, Miami, and Dallas all wining. That will lock in pick 21. The pick drops a slot for each of those teams that lose in the first round and if Houston wins it'll be in the 25-28 range depending on how the 2nd round goes.