This is flawed logic, first off it's not a big accomplishment to avoid the iron sand, as that attack wasn't known for its speed,
second sakura had three, THREE... antidotes, and her and chiyo both needed at least one!
third, with 100 puppet technique it is possible to surround guy with such a range of puppets, he's trapped then there is nowhere to run, no matter how fast.
Sasori is an S class ninja that took out the Third Kazekage, and you don't think he could hit Guy once?
EDIT: like I said without knowledge-->sasori
with knowledge--> Guy
The OP didn't specify knowledge so I asumed full knowledge for both characters. Sasori defeated the third Kazekage off panel, we have no idea about the circumstances. Futhermore, there is nothing to suggest Gai couldn;t do the same.
When did I say Iron sand was known for its speed? I'm just saying Gai can react to it with ease, especially with gates. Sakura and Chiyo had antidotes, ok?
You do realise Sasori is superior to either of them, so managing to land blows on them eventually is nothing to sing home about.
Gai is FAR above Sakura/Chiyo's level, hitting someone of his calibre will be difficult.
And you asume Sasori starts the fight with his puppets summoned? You do realise he might be blitzed before that even happens. Futhermore, Gai can destroy and react to the puppets.
Don't underestimate the gates.
The final gate was said to surpass the power of the hokages by Kakashi. Kakashi's sensei was Minato, so that's huge hype right there. 7 and 6 aint too far below 8, and we've seen Kakashi and Gai duke it out with V2 Jins who posessed sharingan and rinnegan.
Gai takes this fight more often than not.