Maybe they're better in different things. I mean, maybe Itachi is better in taijutsu more than Shisui but Shisui is better in genjutsu than Itachi. So if ever they fight, we have no idea who'll win. Or maybe they'll just have a tie.
Stronger as in Phiscal strentgh. But i think Itachi Can Kill Him.of course not nagato is stornger than itachi
I agree with you some people are misunderstanding SHISHUI WAS BETTER IN GENJUTSU THEN ITACHI.No.
1) His genjutsu is the strongest, yes.
2) He is weaker than Itachi in Ninjutsu and Taijutsu, probably. (Since Danzo managed to get one of his eyes even when he was still a young Uchiha this means that Danzo > Shisui. Or worse. Danzo's Henchmen > Shisui xd.
3) There is no way in the coldest of hells that Danzo > Itachi so.
Itachi > Shisui (Except for in a Genjutsu battle where Shisui wins. Otherwise it's been shown that he's weaker than Itachi in other areas.