Lmao any scenario is possible. Wall Palm>>>Rotation>>>>>>Air-palm in linear defense/offense. Imagine Momo flying away only to get hit in the back by Wall palm which he cant even absorb. Also the smaller the target the more damage Wall palm gives , put any ninja in the middle of a Wall palm and they would get killed by only the flying debris much less the blast itself.
I think Air Palm is made of Chakra since Kaguya's attack seems to have retconned it from being a shockwave that is compressed by Chakra (what the databook 3 says) to being a blast of Chakra shot out of the palm (what databook 4 says). idk.
-Also if Hinata does have Hamura chakra , then im pretty sure that her Air-palm would be way above Hiashi's wall palm , but wat about a Rikudo amped Wall palm itself? What if she needs a stronger Air-palm and doesn't know Wall palm?
I don't think Wall Palm is difficult technique to learn. It is available to the Side family unlike TLF or 64 Palms, so that alone should be proof it is comparatively simpler. It is simply putting Chakra into the palm and releasing it, and given that techniques like TLF and Rotation are more complex in that regard, I think most Hyugas can do it. Hinata and Neji probably just combine their Air Palms during the war to save stamina.
Just want to say that i wish Kishi had the Hyuga send a bit of Jyuken into the Air-palm as it would've been a nice touch after Neji did wat he did to Kidomaru by sending Jyuken through the string. Makes sense that a genius of his level after such a battle would've invented Air-palm himself as a ranged gentle fist kinda like how Sasuke tweaked his Chidori. Not to mention Air-palm makes perfect sense as a ranged GF since the user compresses Air using GF , then sends the compressed air flying via high-speed thrust , Kishi could've easily had the Hyuga place a bit of Jyuken while compressing the air w/Jyuken , to send it flying along with the Air-palm hence the name. Its also funny that the only new tech Neji showed as a genius throughout the whole series after the CE , was an underpowered Air-palm LMAO...
Does seem like Air palm was retconned a bit due to Kaguya's God palm , since she loads Chakra into her fist similar to Hyuga loading Chakra into fist to compress the air. She does the same thing only she loads a hella lot more Chakra as the databook notes , then she sends it flying via vacuum shells which is basically fits the desciption of wat i said above , so idk..
Neji definitely should have been given his own techniques to develop, but tbh sometimes I think Kishimoto had to ignore him and other Hyuga because of how strong he made them in Part 1. I mean, Gentle Fist damage on 3 y/o baby = Gentle Fist damage on Madara since it was established it can't be tanked or trained. You will have to have high-speed regeneration as the only counter, like Kaguya Clan, Juubi Jinchuriki, or Byakigo. Then combine that untankable power with all-seeing eye, Ninjutsu destruction with Gentle Fist, and unmatched Taijutsu, and the Hyuga are easily broken as hell. This is why Kishimoto is ignoring and not giving most Ootsutsuki Gentle Fist abilities.
Neji also showed One Blow Body iirc during the war, so there is that too.
As for Air Palm possibly being like a ranged Gentle Fist, it would be cool. Maybe we will get Twin Lions/Air Palm combo to act like the way you are describing Air Palm and be a ranged Gentle Fist technique. Though realistically speaking, a ranged Gentle Fist attack can't close Chakra points or damage organs since those require extreme precision.