I’d like to see two different hero classes on one team, it’s a good idea and could provide a whole new tactic for guild wars and defence teams.
Warlord would be better served (definitely at least thematically) by Armored instead of Big. +3 attack and life on skull matches regardless of position would be a good boost for his trait, even given similar options.
Knight might be okay with +2 armor to all allies per turn. Armor is the weakest stat unless you have an ally that can turn it into damage, and while Knights have some, others would benefit from this as well.
I feel like Warden could be threatening with something as simple as +5 to all stats for allied beasts. Giving them barrier at match start steps on their best existing synergy. I’m sure there is a better option here though. Maybe something strange like “all allies count as beasts” to open up a host of new possibilities via Forest Guardian (although it would have to be carefully considered given it is a two-troop setup that allows “fast” for any two additional troops).
Sorcerer could change to 50% chance for each ally to gain 1 magic at the start of the turn. Yes, Bard does all stats and every turn, but colorless allows for way more synergies.
Priest could heal 2 HP and increase life by 1 on all allies at the start of the turn. Given that a lot of damage tends to come in bursts, even more and more at earlier stages of the game, healing is more and more depreciated. A cleanse every turn would be way more useful, but I believe that would be best served for a future class.
As for Necromacer, getting such a pittance of souls on match 4/5 feels like a trait you’d see on an epic or ultra-rare something at this point (even at 3, it is still rather pitiful - you don’t end up with many souls if used by itself, and if you have a soul gen you don’t really need it). Thus, I feel that Ensoul could replace his first trait, and his final trait could be a +100% necromancy trait.
That leaves some classes with “legendary” level traits and some with “mythic” level traits, but in the end I feel that that is okay so long as each of them has a broad use. Most would still likely be underused at endgame, but mostly because building bulk is not that great of a strategy especially if you are trying to win quickly.