I think Kishi would at least make it more obvious where the characters stand. They would either all be instantly negged at the start of the arc, or getting W´s against the SHP.
It´s hard to imagine a Shanks vs Mihawk situation in Naruto, with both characters being alive at the same time and it being debated for 30 years. If Kishi was writing, Shanks would either be scared of arriving at MF and meeting Mihawk, or Mihawk would have genuinely lost to diamond Jozu in MF, and no one would be sure how that´s supposed to make sense.
If Oda wrote the Akatsuki:
Deidara would get low diffed by Gaara and use a hostage to land a cheapshot to knock Gaara out
Sasori would emotionally manipulate Granny Chiyo into letting her guard down before taking her out, and then Sakura would solo him and cure Chiyo with a magic antidote that she invented offscreen.
Hidan would go out the same way, but Asuma would be revealed to have survived at the end of the arc.
Kakuzu would be already losing to Kakashi before Naruto comes in
Gai wouldn’t even need to activate the Gates to beat Kisame
Konan’s cup size would be 10x bigger and she wouldn’t be wearing an Akatsuki robe for some reason
Obito would lose an arm to Kiba and Shino in his introduction