Healthy itachi vs 3rd raikage who would survive in a fight

[Hokage Uchiha Sasuke]

Itachi extreme diff.

His only way of putting sandaime down is genjutsu and weʻve seen how hard it is to put Ei into one. MS techniques weaken his body allowing someone like sandaime to blitz him in the downtime, susanoo isnʻt withstanding a nukite unless it blocks it first with yaata.

Itachi can't blitz any MS jutsus, he still will suffer the side effects of the jutsus such as pain, large chakra usage, and losing his eye sight. Sasuke was keeping up to Itachi's speed while he couldn't even react to A's speed and Naruto compared the 3rd Raikage speed with A's speed. Itachi wouldn't keep up with the 3rd Raikage speed and his lightning blade strike might even break Susanoo.

Are we forgetting Tsukuyomi is a mangekyou sharingan genjutsu that lasts an instant?