@Grahav "Hybrid Vigor" (Heterosis) is actually a defined concept in the field of evolutionary research. Its best know within plants, but it occurs elsewhere as well.
When looking at hybrids, its is also important to account for evolutionary histories of the genus involved (as it influences if individual species have had time to separate and evolve genetic (pre/post gamete infertility).
Example:
--- Panthera is estimated to have first started to diverge into its separate species (lions, tigers, jaguars) around 6.4 million years ago.
--- Equus species (donkey, horse) started diverging around 5 million years ago
--- The genus with humans (Homo) however only started diverging 3.4 million years ago and our species as we are now only started diverging from other species in the Homo genus 500,000 years ago. With introgressive mixing (where hybrids could reproduce back with either population) continuing until 50,000 or so years ago.
Its fair to say then that hybridisation between Pandera species =/= hybridisation between hominid species. These are fantasy races so its futile to really go deep on the outcomes of hybridisation between them when we have no idea how distant they are in evolutionary history, but it doesn't seem that unlikely for a "vigorous" hybrid coming of it.