Great job making changes to the way I can track my collection!
Unfortunatelly, I have to agree with people who posted here, there may be a bug.
According to the WoWProgress site I have 235 pets at 25 level. Warcraftpets summary at the same time shows 212 pets at max level. The issue here are not duplicates as WoWProgress doesn't show duplicates and I am sure that I don't have any at max level.
When I tried just to "manually" count the max level pets in my collection on Warcraftpets I counted 234 (but I may be wrong as it is really hard to count with all this colors and small digits

), what is still more than 212 in the summary.
I also calculated average pet level (including all quailties, but exluding non-combat pets and duplicates - again based on data from WoWProgress) - 16,3 - and it also higher than in summary - 15,8.
Edit: typos