(...hope I'm answering this right ... not sure about your question ... )
Nice listing on that link. I think it will update even more and better with another month or so in Legion since some of the pets in there are showing a small percentage and they seem to be a bit more up front than otherwise.
I use the Pet Search site and pull out the spreadsheet from it, which is MASSIVE help, and you can organize things from there. On another posting I have how I did this, as did others, but generally, since I am clearing out the stuff that is not Rare, I remove the 25's that are Rare (and already 25) from the list and organize the rest, so I know where to use the Pet Charms on, as well as level. Once 25 they go off the list since I do not need to check them again. Thus, if you check my list, it dwindles down to 149 Rare's to level to 25 and 71 or 72 Uncommon's only left to Upgrade and finish leveling. This spreadsheet helped me clean up the Poor's and Common's real quick! But the Uncommon's are another chore ... over 40 of them are Vendor/Store/Quest pick ups.
The nicer thing, is that if you have some Poor's, Common's and Uncommon's in your list, in Legion, you have a good chance of updating those in your collection, instead of running around Pandaria or Draenor and hope to get one to cover ... plenty of many of those critters and beasts as the left overs pets in Legion.
IF, the information you wanted was which pets are tougher/better, I would start from the Top 20 on this website. But, in general, any suggestions for the bigger fights are already marked by me as "must have".