While I am still new to the game and I only have Mei Feng as my only Ten Thunders Master, but I tend to agree that she with Kang as the Henchman tends to provide a counter to Rezzer crews. With Kang's auras, he can give other models within him a positive flip on melee attack and damage flips on models with the Undead or Construct characteristic within 6'' of him. As well, his other Aura gives all friendly living models within 6'' inches of him immunity to horror duels. With Toshiro, he can give a positive flip for friendly minion models, along with the ability to give them Fast or the Focused condition (for a trade for a Corpse or friendly scheme marker.
If you plan on running a Mei Feng crew in the future, make sure to take models that have the Foundry characteristic and the Hard Worker upgrade on Kang. This way you can use Precise Assault to ignore any models that have Armor or Hard to wound (keep in mind it does not negate Impossible to Wound).
Well, hope it helps!