What move are you refering to? I can't see any move in Sasukes arsenal that would have a hit ratio anywhere near that against Gaara.
Your whole thing about the difference in Madara and Sasuke fighting styles. What do you base this on? What similar moves are you refering to?
We have compared Gaaras sheild against Sasukes susanoos sword attack. The ranged one we've ignored since there isn't a case where his sheild's been hit by a susanoo arrow.
We've not seen a chidori penetrate the sand sheild since chuunin exams and that was VERY long ago and only once. it's not even sure that it would penetrate his sheild if he was expecting it. Maybe he could make it thicker even then and there. and it's almost certain that his defenses has gotten stronger the last years.
Amaterasu isn't pericing anything, besides we've covered it.
The whole thing about Onooki is basically an assumption as far as I can tell, you don't even know for sure that ligthening the sand was for the purpose of making it possible to pull him out, it might've been to make sure he couldn't evade the sand, making the move quicker or something else. No where does it say or show that he can't be pulled out with regular sand.
I guess i was to vague because i didn't want to post something extremely long. I guess i will use more details now.
Madara's and sasuke's fighting styles are very much different even though they pretty much have the same moves( except for rinnegan, wood element, and PS)with some differences of course. Madara basically wants to completely destroy you until nothing is left. Sasuke on the other hand move set revolves on the fact that 90% of all his moves are piercing attacks. Enton and ammy solely moves will have no effect on gaara auto defense.
Like i already said gaara's main flaw is his biggest strength. Gaara doesn't move and this will cause him to get the L. Sasuke susanoo arrows are fast and they pierce everything. If you can name one thing that it has not pierced up to date then i could say that gaara's defense could stand against the arrows. But if you re look at the whole kabuto dodging the arrows and the arrows hitting the pillar, you can see that the pillar was not destroyed. This proves that sasuke arrows are only meant to deal a piercing blow that happens to be quite fatal. Now wrapping his susanoo arrow in the enton would prove a devastating attack to gaara, due to the fact that he would be a stationary target.
Now lets explain in air combat
In air gaara has limited sand so his scale of attacks dwindle by a reasonable margin. He is still quite strong in air but sasuke with the help of a summon can also take the fight to the skies. Without actually seeing sasuke fight in the skies we can not deduce how well he fights in the skies. The only problem with this scenario is that gaara doesn't fly unless he is a) fighting someone who flies or b) trying to escape from a large scale environmental like attack( ex. advent of the world of flowering trees). With these conclusions it is very likely that sasuke vs gaara will only be on land.
Yes gaara's defense has gotten a lot stronger but if you think sasuke's chidori is the same as it was when they fought during the chunnin exams then we are not reading the same manga. Just like gaara sasuke has gotten a lot stronger since their first encounter during the chunnin exam.
Now based on gaara's reaction to his sand being lightened and the fact that he never tried it again after his sand returned to normal, gives me the impression that his sand needs to be lightened in order to throw someone out of susanoo.
If u need manga scans it would be a bother but i can provide for some of my points, but only if you truly need scans.