Sure, why not? I mean, Pein (a much weaker guy) did manage to solo a stronger village by himself so (ok he had Konan's help, but he did like 90% of the job and Hashi is stronger than both together)...
Hashirama uses jukai koutan to turn the desert into a forest. This removes Gaara's ability to use sand from the environment, forcing him to rely on his gourd sand. Hashirama is a sensor and can fuse with his own trees through attack prevention whereas his opponents can be susceptible to surprise attacks. Mokujin was stalemating with perfect susanoo whose attacks can slice mountains so it too has enough firepower to obliterate the sand village and tank all his opponents' attacks.
Hashirama cant beat gaara in the dessert, and they basically have the same power. Even if hashirama creates a forest in a instant, this is nothing for gaara as he can create a dessert in a instant as well.
Gaara would take this battle and it is a definate win with the sand village (kankuro, sasori, Chiyo, 3rd & 4th kazekages) backing him up.