Naruto takes all rounds.
Round 1: While the Shanks clone is busy with 50 clones+3 giant frogs Naruto can and will blindside him with a RS like he did to Kakuzu in base, a guy who's much faster and more experienced than Shanks uh I mean Gildfarts...Gildarts
Round 2: Shan-Gildarts gets blown up. He got his ass handed by a random featless dragon and the ones shown in the Grand Magic games arc were pathetic. All they did was cause collateral damage.
Round 3: Gildarts loses so bad it's not even funny
@5th:Okay Explain this one to me because I thought that Gildarts was Sage Naruto's equal and that he could at the very least survive against chakra mode.
The only thing Gildarts has going for him is his destructive capabilities and that's it. Sage Naruto can distract him with 50 clones and throw a rasenshuriken at the back of his head scrambling his brain.
Gildarts vs base Naruto would be a better fight