Protagonist_1
Champion
Good topic. Most of the time (but not all the time) instant-air light attacks are faster and beat out medium and heavy attacks (and medium attacks beat out heavies...usually). Although, one of the disadvantages for going for an air-to-air is if your opponent doesn't jump then it's very easy for your opponent to anti-air on the way down. Some characters can even use normals (like standing 1) to anti-air early jump attacks.It depends. It's not just about the faster attack, but range, hitbox, timing, etc...matter. It's not as easy to determine as grounded attacks, where you simply look at frame data. Also, part of it is determined by who initiates the jump (for example, even though I brought up Lex's J3, it won't beat J2 if Batman jumps first since Lex's jump is pretty slow). Deathstroke's J3 outranges Batman's J2, so from certain distances, it will beat it. That's kinda why I said there's no such thing as "Move A ALWAYS beats Move B" in air to air, not in most situations anyway.
One thing you're definitely right about, Batman's J2 is good at beating out Deathstroke's jump back 3 in many situations.
I honestly can't answer your question for sure about DS' J3 vs Batman's J2 as an absolute, so you might be right, I need to test this further. But yeah, DS' J1 beats Batman's J2.
EDIT: Nah, you're right lol. Did some quick testing. In most cases, J2 will beat DS' J3. I apologize @HomeLee1121 @Vagrant
Plus, as you mentioned before, the hitbox is a huge factor. For example, weapon attacks do not have a hurtbox, only a hitbox. This means they have priority over limbs, hence why Deathstroke's j3 and other characters with weapons with jump in attacks are difficult to anti-air.
You can also say the same about anti-airs as well involving weapons. This is why batman's j2 gets outprioritized(beat out) by Aquaman's d2, due the hitbox of the trident being a weapon and having priority over limbs.
Thinking about it now, how you anti-air in a match is entirely match-up specific, unlike mk9. Different jump in attacks must be anti-aired at different ranges or challenged with air-to-airs to beat them out due to the various jump-arcs and hitboxes of jump in attacks. I actually want to make a thread dedicated to this, but didn't have the time. Although it's probably common knowledge not everyone knows this unfortunately.