Except, Jacob wasn't oneshotted by Natsu, he was landed multiple strikes froom other characters and took damage from them, that doesn't indicate Oneshot to me.. and just because Jacob is a spriggan level opponent doesn't mean he has impressive durability considering he hasn't shown to be a tank. So you're really not giving Gray any benefit of doubt here. I do agree that Natsu's team wins but it's mostly because of him, and it's a lot closer than you think. I'm pretty sure Gray has a higher defensive barriers in his arsenal than Ice shield btw. Natsu doesn't have better versatility also. Gray's intellect, versatility and portrayal makes this a high diff fight atleast against Base Natsu.
You missed that point of my post. What I mean is that one FDKM FDK demolition fist would be more than enough to put Jacob away as the attacks landed on Jacob before did minimal damage. It was the one serious attack Natsu used against Jacob, and it put him away.
As for Versatility, I'd say Natsu definitely has the better versatility when you consider he has Flame and Lightning to Gray's Ice. Two elements to one puts Natsu over for Versatility.
Gray's intellect won't really help him much in this fight when it comes to Natsu imo, as even if he does try and use ice clones, Natsu can smell out the real one or hear the real Gray's breathing and just go and attack that one, hence that sort of strategy won't work. Plus, Lucy's intellect can probably match Gray's from what we've seen, so he's got a match there in that department.
Portrayal wise and feat wise, again Natsu would beat both Gray and Juvia. Natsu's simply shown a lot more when it comes to attack power and that really would put Natsu and Lucy well over for the win. I'd say Natsu is definitely a fair bit stronger than Gray feat-wise so far, and I'd say Lucy is stronger than Juvia. Putting that together, this fight goes to Natsu and Lucy mid-diff imo.
I mean sure,that's why Horologium showed up when Ajeel was about to kill them,right?
@SirSamuel016 Smell can't detect clones,huh?Natsu attacked Lyon in Galuna Island only to find out it wad a clone,if he had the ability to sniff out clones pretty sure he wouldn't have leapt instantly at Lyon..
Also Gray doesn't exactly have horrible durability,he took several of Rufus's attacks without going down and even proceeded to go and fight Lyon and Sherria in the GMG,his durability is pretty much up there...
Well their attacks are really nothing to the level of attacks that FDKM Natsu would be throwing out, and I doubt Gray's durability which hasn't shown to have improved too much since then would last up too long. Its a pretty weak example there imo.
As for your point on the clones, as I've already mentioned, Natsu also has hearing which would allow him to find the real Gray from an ice clone. His sensory stuff has been shown to have improved a lot, so there's no reason why that would still be the case now.