The best breed really depends on the comp you are running. For example, if you are using Magical Crawdad and are hoping to play the long-game, the H/H Val'kyr is better. If you are playing aggro, the B/B Val'kyr will probably be stronger.

The first team you listed looks good. As you mentioned, its versatile - it will give you a chance to win every game. It also allows you to play from behind if things start off poorly. The Jademist team, on the other hand, seems fragile. Death Adder and Jademist both have low HP, and can be 2-shotted...

i love my team, and even though its not the most OP one out there i think its quite fun to play: -Unborn Valk'yr (2,2,1) -Scourged whelpling (2,2,1) -Clockwork Gnome(2,2,1) i was at first switching around my first pet with pets that matched oponents i saw myself going up against alot, but the valk ...

I didn't look up strategies the first time I completed it (had approximately 28-30 max-level pets). I really wanted the full Celestial Tournament experience, complete with all the tears and rage. Ultimately, it was worth. I learned much more about pet battles by critically thinking and experimenting...