Dallas’ playoff schedule is terrible, they are the second worst option of all teams in the NFL, going by schedule.
The Niners’ schedule is mediocre, and I see little reason to believe they will overperform.
KC looks good, though. Going by schedule alone, they are the 5th best option right now. The only teams that have even better week 16/17 schedules are:
Cleveland, Detroit, Miami and the Chargers. But none of them are performing above expectations at the moment, so the good schedule may not help boosting their performance. Same for the Raiders, whose week 16/17 schedule also looks good, while their actual defense does not.
I’d roll with KC here. Baltimore and Buffalo would be good alternatives, as both defenses are performing above expectation, based on their previous schedule. Buffalo has a great matchup in week 16, Baltimore in week 17. So if you have a chance to stash one of them at any point, do it.