I don't think we need a 9th tribe, but, I reckon treants and totems might have their spot.
Either way, the official patch is in a few hours, which might include buffs/nerfs.
However, I wouldn't get my hopes up just yet. If out of cards' data miners mined -only- the tier 5 levelling change (goes up to 11, rest remain as are), albeit mining all buddies (though tribes pensing), seems like avenge meta contonues.
Doesn't really need a new tribe, I think they should have done something about Dazzling Lightspawn, either avenge 3 or tier 5. But so far from watching the streams the buddies seem pretty interesting, even if they do speed up the game and make gaming on mobile even more awkward.