It’s kinda hard using a yellow team when you keep exploding all the Yellow, you begin to notice that your troops are very slow to fill despite using a mass exploder. And after a couple of Herdmaster’s casts you end up with a board with no yellows. You need a yellow gem spawner to use Herdmaster effectivelly IMO, like Queen aurora or sehkma.
Edit: Clockwork Knight and Desert Mantis can also do the job