Without restrictions, this is a spite. No one from the Gokage can counter Senpō: Hakugeki no Jutsu, Manda II nor Mateki: Mugen Onsa. With that being said, all summons and jutsu that are too big for Kabuto to handle, are annihilated by Manda, including Katsuyu. This restricts Tsunade from using Katsuyu and Ōnoki defending himself, and the Gokage with various of techniques, such as Doton: Gōremu no Jutsu.
Ei's speed is nothing special. We have seen many ninja's keeping up with his V1, and in V2 state Kabuto's precognitive abilities help him react in many ways. Even if he does land a hit, Hōzuki clan's Suika no Jutsu renders his and Tsunade's Nin/Taijutsu useless.
Gaara most likely is the toughest one to beat, but not impossible. We've seen that Gaara's defense cannot be penetrated that easily, so Mateki: Mugen Onsa does the trick. As for his sand, everytime it approaches him and he is managed to get caught, he can use either Suika no Jutsu to slip away or Senpō: Muki Tensei to control inorganic sand with his life force and loosen the bind.
Either way, Gokage have no chance of winning this match, it can be ended with two techniques.
