This makes sense if we had a really good “perfect imbalance” in the game, a “rock, paper, scissors balance” if you prefer. But even then, some troops would still be better to use on attack simply due rarities(power), style of play, sinergies, countering the enemies and weightening advantages, incentives and disadvantages in some restricted scenarios.
For the first possibility, if those traits are working as intended as a form to add some disadvantage to really powerfull troops i can only see Greedy fitting into this, as he provides support for Gold/Merchant/Money Bags strategies, which is totally fine and awesome as you consider the sinergy with the Rogues/Pirates all getting along.
But some of the other sins doesn’t feels really good at their own sinergies for their themes specially on defense thanks to how the “Omen of____” traits are working.
Side note: Wrath also works pretty fine, wrecking stuff (exploding gems) when matching skulls, but on the other hand Lust feels really lackluster thanks to how costly her spell is and because her trait only work on allies’ deaths, if it was on any death then she would be really good, but we would have some problems with teams using two Lusts that could cause some insta-death chains with Firebombs…