Probably shukaku and matatabi. the biggest gap in power comes from the later tailed beasts from the 8 and 9 tails. idk how strong the 7 tails is in comparison to the 6th but the top two are leagues above the rest

Matabi is pretty fodder cuz fire won’t do anything against water and if we’re going off one piece logic shukaku sand attacks won’t do shit when wet but he also has wind style so this fight is basically a fight of wind and water on a mountain level scale

But this isn't one piece... so its logic doesn't exactly work here in the Naruto world. also its been shown that water jutsu can be overpowered by fire jutsu and that wind jutsu can power up fire style jutsu. so if shukaku were to help power up matatabi's fire jutsu then they could overpower isobu's water jutsu

Maybe