The F2 skill for cat can not be released instantly, it seems need a channel. But its other skill can be done with auto attack together, which means you can see 2attack pop together, it is auto attack and a skill damage
For bird, its F2 skill is much faster or even instant released for next attack. But its other skills will cover its auto attack which reduce its overall damage significantly.
And its attack mode, fly back after attack, this just draws some distance from the target, bird does have a siginificant advantage on hitting moving target.
And BTW, all the bleed condition for pet is not bonus from anything. I have dropped this issue for over a week, but nothing has been solved, not even an answer in my bug report.