#1The OC
The OC seems to be the most obvious choice to challenge for The Viking Raiders' RAW Tag Team Championships. They did become "The Best Tag Team in The World" when they defeated Erik and Ivar and several other tag teams in a gauntlet match at Crown Jewel, and that victory makes them the only team on RAW to defeat The Viking Raiders.
So, these accolades seem to justify a title shot for Anderson and Gallows, and since Styles does not have a match (as of this writing) at TLC, that can allow them to solely focus on The Viking Raiders. Also, it will help to have AJ Styles in their corner when facing such an imposing threat in the form of The Viking Raiders.
Gallows and Anderson may be helping Styles in his feuds against Randy Orton and Rey Mysterio, but they have mentioned in backstage segments that they will eventually go after The Viking Raiders' Tag Team Championships. It seems like an open challenge at TLC would be the best opportunity for The OC to live up to that promise.
The Viking Raiders issued the challenge, and now the only question is: Who will accept? Honestly, with the way The Viking Raiders have been decimating their opponents, it may not even matter! They are looking to continue their raid as RAW Tag Team Champions heading into 2020, and it doesn't look like anyone is going to stop them.