It's decreased over time, as Naruto's power has increased proportionally more as things go on in it's series than OP's has.
The best matchup here is probably Jonin Neji vs beginning Zoro. Jonin Neji's more dangerous than a lot of people Zoro fought in the East Blue (granted, Zoro won't start out stabbed or otherwise wounded in this fight...).
Early on, Zoro has a lot of strength but he can neither do shockwave attacks or slice through steel, so Neji's defense might actually be a major problem for him.
It these two particular characters I think Neji has got exactly one upgrade while Zoro has at least two minor upgrades -cutting steel and that nine-sword strike- and is going to get his first big one in a few weeks. Jonin Neji vs East-blue Zoro sounds about right.
I don't think any OP character could do that, at least not and be assured of success, what with all the hax abilities. Kizaru or Enel'd probably be the most likely to pull it off, but even someone like Whitebeard wouldn't be able to.
But anyway, I'm talking more general level than just the few top characters. The strength difference between the genin that made up 80% of the fighting pre-time skip, and the fighting we've seen recently (be it S-class, or just post-timeskip versions of prior characters), is huge. It represents a significant increase in stats across the board, speed, strength, and jutsu, Shippuden Naruto could beat starting Naruto with one hand tied behind his back and his eyes closed, and a Jonin like Neji could probably take the Rookie 9 as-of the chunin exams pretty easily. The Naruto characters started weak and became a lot stronger.
The gap between the Strawhat crew starting out and post-Skypiea crew is comparatively small, incremental increases. They got one sizable power up around Water 7, but not . Crocodile could be fought successfully right after they entered the Grand Line, and they've still not reached his level of power, just gotten closer to it. They're stronger, but they started strong to begin with and haven't gotten to the point where they could brush their old selves aside, so their power hasn't had the same proportional increase.
Drop current Naruto in OP and he's a badass. Not many pirates we've seen could stand up to him, only the really top pirates and navy people.
Drop early Naruto into OP, even early OP, and while he has an interesting ability, he's pretty weak.
He's one of the most increased of the crew, or at least the strong members.
Usopp and Nami get pretty big increases, but they started with almost nothing.
Also worth noting, Luffy does have superhuman strength.
Enel could not be so much as harmed by most Naruto characters, and could one damn near any of them, and many of them at once. If he gets Maxim, lol. Whitebeard could pretty easily do it. He could destroy entire villages with a single attack in ways that make Pain look like child's-play, the hardest part would be walking to each separate village.
This is true.
This is not true. It is directly stated by Oda that with each arc, the crew gets progressively stronger. This is even brought up by Zoro, noting that without even realising it, they have each gotten stronger. Crocodile could be fought once his weakness was discovered, yes, but overall he is still noticeably above the crewmates individually, and he is arguably the weakest Shichibukai. Let's think of Boa Hancock, who was able to easily destroy Pacifista left and right, it took the crew working in tandem to take out one.
Luffy did the equivelant Sage Mode Naruto's best strength feat in the Arlong arc. He has only gotten stronger. Any Shichibukai would effortlessly dispatch him, even Arlong, based on his fight with Luffy, may give him trouble. Although it is hard to say now, since we do not know what Naruto's latest powerup entirely means. One Piece characters are also much faster than Naruto characters, considerably.
High-end Naruto characters -those we've seen at least- are able to hang with some of the OP characters, it's a weird balance because Narutoverse has versatility in spades while OP tends to be more focused in certain aspects.
By looking at Crocodile's feats during the War arc, I'd say he may be able to hang with Moria and maybe with Hancock. I wouldn't put it past some of the high end OP characters to solo the Narutoverse if they have the right information about the opposition.
I personally think that Rayleigh is stronger than Shanks, and Kizaru stalemated Rayleigh, and Marco stalemated Kizaru, yet Garp was able to pwn Marco even in phoenix form...
Garp is awesome!...
as for the topic, any version of Zoro destroys Neji...
I don't think any of Whitebeard's attacks did more damage than Pain's. The largest one was shaking up Marineford.
Let's also not forget genjutsu, soul removal, kamui, etc..
There's more to a fight than mass destruction.
I'm not saying they aren't getting stronger, just that difference isn't as huge.
How many times stronger do you think current Luffy is than starting his voyage? East Blue Luffy could still put up some fight IMO.
Now, compare to the difference between Zabuza saga Naruto and Sage Naruto (or heck, even non-sage Shippuden Naruto). 50 of him would be useless against Sage Naruto.
He's got a lot more than strength, his primary attack is rasenshuriken after all... and I think the Summon-tossing is more than the strength shown in the Arlong arc.
I think Sage Naruto'd pretty solidly beat Arlong.
What's the speed of OP characters? They're faster than part 1 Naruto characters, but I'm not sure if the same can be said of the higher speed Naruto ones, the difference doesn't look all that huge to me.
1. Pain destroyed Konoha (Which is not that big), and made a small mountain with Chibaku Tensei. Whitebeard casually quaked Marineford and the sea beyond it, and could easily cause tidal waves by creating quakes on the bottom of the ocean that would have envoloped and destroyed much or all of Marineford, if not for Aokiji.
I was going to get a scan, but apparently M@ngaf0x is no longer hosting it. Ghey.
Genjutsu is so laughably useless in damn near all cases that do not involve a Sharingan, and you forget that certain sufficiently powerful characters, Whitebeard, Kuma, Enel, Kizaru, etc., are at the very least powerful enough to kill any Naruto character near them. Soul removal is only useable by one of Pain's bodies, and I guess the Gedo Maizo or however you spell it, which Pain would never get the chance to use and cannot use in his last seen form. As for Kamui, only Kakashi and Madara have abilities kind of like that, Kakashi would never get the chance to use it (What with Konoha being instantly obliterated), though Madara admittedly might be cheap enough to pull it off, though it is not foolproof as we have seen, and many OP characters could take him out before he could use it.
I know, only OP characters also have speed to their advantage, which allows them to use their destructive attacks before Naruto can truly implement their greater versatility, this combined with their relatively shitty durability means Narutoverse would be ****ed against some OP characters.
2. Much stronger. There is not even a comparison. Higher base physical stats, Gears, and Haki make current Luffy make East Blue Luffy look irrelevant. EB Luffy had trouble fighting Arlong, whereas current Luffy can at least hang with some of the higher tiers in OP now, although he is not as strong as he will be end of series, though there will probably be a time skip so he can master Haki, as you know. That is the main difference between Naruto and One Piece, the main cast of Naruto (Read: Naruto, Sasuke, and Kakashi, Sakura does not count) are pretty much at the top of the verse's tier overall, though with other contenders. The Strawhat crew does not begin to compare to the truly monstrous characters in OP, as the Marineford arc served to demonstrate.
3. I agree, mostly due to versatility, but again, Arlong would still put up a fight, due to similar physical stats.
4. Kalifa as I mentioned is calced to be like mach 9 I think, but even near the start of the manga, Luffy could intercept bullets by moving like a hundred or so meters, when marines were firing at Zoro and Coby from only 20 feet away. They were flintlocks admittedly, but that is the beginning of the manga.