The below lists show pets most commonly used in strategies on Xu-Fu.
They are by no means an ultimate guide, but should give you a good indication of their importance and usefulness in PvE pet battles.
This is spookily close to my T1 and T2 lists. Just a couple of differences, and the commonality I find most interesting is the number in each tier. There does seem to be a natural break after about 15 pets.
My suggestion is that this list badly needs suggested and preferred breeds, for any newcomer who might use it for guidance.
That's a great point! I hadn't thought of that. While the site does allow for breed requirements, there are also other constraints like minimum speed or power that are hard or misleading to capture in a list derived from the data.
And indeed breed is not always so simple, and we do keep different breeds for different cases.
I'll drop in the survey answers for the species mentioned in these lists, as a comment, at least. I think it's safe to say that a newcomer will not regret choosing the most popular breed of a species.