I’m not sure where to begin with Tau, I feel he should gain attack based on number of enemies remaining or enemy knights, and gain enraged if 2 or less enemies remaining. Should give him that ‘challenger’ feeling.
Wild Fang, just let us target the spell like Lord Ironbeards. Random is fine on Gnoll, the chief would be a tad more accurate with that Axe. 
Orc Veteran
I don’t hate Orc Veteran after play testing it a few days ago.
Would like to see:
Yeah I reckon he’s not too bad.
In my Orc PvP team he can sometimes loop himself +5 times in a row once you prime the board with Gar’Nok. Certainly, I find getting two to three casts in a row somewhat regularly.
I think the firebrand trait is good for that little bit of extra attack at the commencement of battle to gain a bit of an edge to begin red spawning. If anything swap it for the Orc Fury trait so not reliant on enemy spell casts and instead double boosts from Gar’Nok.
Or even instead of the Orc Fury give him Orc Cunning so his damage will increase. 
Infernus
I don’t know if he was covered yet, but my favorite troop in the game and not a thing needs changed at all with him.
and now even better when paired wth Divine Ishbaala 