Overall, i give this to Gaara with High-difficult. The mains problems here for Gaara are Equake, Stats Amps, Rollout, Poison Sting, Protect, Sandstorm, Swift and maybe Dig, but his range and intelligence advantage should give a win for him, while the Stats amps are really good, Equake could possibly hit Gaara under his shield, and Rollout could possibly pass through Gaara' Shield of Sand and Armor of Sand after some hits. Poison Sting could Poison Gaara, and that would really screw him up, Protect can protect Sandshrew, but the fact that is not spammable is what kinda let him less usefull and Dig could be used to avoid some of Gaara's attacks, though Gaara could likely pull Sandshrew out of the hole with his Sand Manipulation. Sandstorm gives Sandshrew a lot of advantage, mainly a speed amp and an evasion Amp, however, i think that Gaara could possibly just use his Sand Manipulation to vanish with the Sandstorm, if he can't, them Sandshrew may have a cahnce, and Swift is a Homing Attack, so that could help, the rest is either bad, outclassed or countered by Gaara's Sand Manipulation. However, the range advantage is too big to be clear out fast, and Gaara may be more intelligent
So Gaara for the First round with High difficult, the second Sandslash problaby blitz
