If he started out like that, he'd be instantly out of chakra while Sasuke would still be fresh. It's easily dodged or completely evaded by being so close to Naruto that if the attack were to be used they'd both get destroyed.People often get confused when us Naruto fans say he lacked killing intent vs sasuke in their final battle.
Naruto stated several times he didn't want to fight sasuke as he was(emo), sasuke himself noted Naruto was holding back/slacking due to no killing intent.
Now imagine Naruto decided to kill sasuke from the start, imagine Naruto went all out before sasuke absorbed the bijuu chakras via preta path/susanoo.
If Naruto decided to start the battle seriously it would've ended very briefly, sasuke would be dead.
Had Naruto started out like this, sasuke have absolutely no counters without the bijuu chakra.
Impossible. Sasuke was far too inexperienced to cast and absorb techniques at the same time.Sasuke can apply all of his abilities to his avatar (Susanoo) ; Like how he used Chidori via his Susanoo :
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So he can use Preta path to absorb that technique (via Susanoo) .... GG
But ofc you will deny ...