not positive if this is a bug or not , can someone explain this

[InsanitrisesAL]

I swapped a pet with 25 percent stacking dmg to a pet with 30 damage not stacking , the 30 has less dex but more damage , if im not mistaken stacking damage should and always has been higher ? Correct me if im wrong , friend also compared draguer to feng and same thing Can someone explain the mechanic behind this , i always remembered stacking was higher than non stacking , am i missing something?