I find these really amusing, so I'll give my quick analysis of how viable each background is in a background-tribal shell.
White
Far Traveler
Only needs one good target, and it naturally synergizes with
Candlekeep Sage.
Flaming Fist
It does the thing. Synergizes with a lot of other combat-oriented backgrounds too.
Folk Hero
There are 2 strong incentives for tribal in backgrounds, so it's not impossible, but tribal is pretty orthogonal to the background strat.
Inspiring Leader
There are quite a few payoffs for tokens in backgrounds, so this seems like a reasonable fit.
Noble Heritage
Doesn't really require work to be solid.
Veteran Soldier
Does work on its own, but also makes a lot of other backgrounds significantly better.
Blue
Candlekeep Sage
Besides
Far Traveler it doesn't have a lot of synergies, but it draws you some cards. It's ok.
Clan Crafter
It's nice with
Guild Artisan, but otherwise it goes it alone.
Dungeon Delver
Nothing else does anything with dungeons, so this is pretty isolated.
Feywild Visitor
Not as easy to activate as
Veteran Soldier, but it does work okay on its own and better with combat and token backgrounds.
Shameless Charlatan
Kind of impossible to synergize with much, but it's a great card.
Sword Coast Sailor
Strong on its own, and synergistic with other backgrounds.
Black
Agent of the Iron Throne
Definitely requires some work, but treasures and creature tokens are both reasonably supported to make it happen.
Agent of the Shadow Thieves
Not nearly as good as
Sword Coast Sailor imo. It synergizes decently with other combat backgrounds though.
Criminal Past
Menace is fine, but you probably aren't planning to be creature dense or self-milling.
Cultist of the Absolute
Could definitely be strong in the right circumstance but having support is pretty mandatory. Really wants
Veteran Soldier or something.
Haunted One
Even without tribal support it's quite strong, and it gets better with them.
Scion of Halaster
It's not amazing but it doesn't require support.
Red
Dragon Cultist
Bit slower than other token producers, but the reward is pretty strong.
Guild Artisan
Synergizes a decent amount of other stuff, or just provides some mana. Does want combat-worthiness.
Passionate Archaeologist
Not a great payoff and requires doing something unusual. Why is this the most expensive background?
Popular Entertainer
Pretty meh payoff and requires some work, but at least it's not super specific.
Street Urchin
My dislike of the wording aside, it works decently with token support, albeit not as strongly as other options.
Tavern Brawler
It does well without support, and can help a bit in combat sometimes.
Green
Acolyte of Bahamut
So we're just casually making it dragon tribal, eh?
Cloakwood Hermit
Really nice for other token synergies, but potentially kinda difficult to trigger.
Hardy Outlander
Not a great card, but there's a fair amount of stuff buffing up our commander to make it stronger.
Master Chef
Good with combat, good with tokens, but not amazing with anything.
Raised by Giants
Nice for combat focus, kinda pricey compared to everything else though.
Colorless
Faceless One
Included for completeness.