I'm going with Tampa Bay.
The storyline of the aging Brady proving that he's still at the top of his game, while having a competitive shootout with a young up-and-coming (Mahomes) quarterback will attract viewership and give the audience something to get behind (without hurting the push, heat, or public appearance of either performer). From a branding and marketing standpoint, this allows Brady to go out on top (good for the brand) and allow Mahomes to come back again in future seasons as the new standard bearer of the league (good for the brand). I don't think the story is quite as compelling if Brady loses.
Also, the Chiefs aren't involved with show Ballers this year, so there's no need to have them win to maintain storyline consistency.