No. Lots are, but once you have a larger collection to choose from, you can make slam-dunk teams against most things.
Some battles are RNG and that’s the challenge. Most, however, are not.
When you hit a battle that is full of “% chance to stun” abilities, you know right away it’s gonna be RNG heavy.
You’re going to be VERY happy about that. Find the ones with the highest speed and/or power, and make sure you know which ones have Call Lightning. Comes in super handy in some places.
Check the Shadowlands and BfA WQ pet battles every day for Blue stone rewards. You can get them for free, and they’re repeatable by every alt you’ve got. In early days of “getting into it,” you will need tons of blue stones, but buying them is a huge outlay in coins. Better to wait for them to be up in the world as WQ rewards and then go farm them for free.
I wrote an entire guide on my WoD daily rotation if you want to see it. It’s in this thread. Scroll down to the hideously long wall of text…ha ha