I think Hitmonchan should simply be a worse Conkeldurr. We all know how effective that set was, and Hitmonchan is the only pokemon that can replicate it. It may not have that meaty 140 Attack stat and that beautiful 105 HP, but it can get by with what it has. The absence of Guts makes this set much worse, but it is still manageable. And compared to Gallade, it doesn't have the same bulk, attack, or speed. But Hitmonchan has several key assets that separates it in a positive way. For one, it has much better speed than Conkeldurr, meaning that slower threats can be Drain Punched, as supposed to needing to use Mach Punch on everything. Hitmonchan also has much better special defense than Conkeldurr, meaning that it can take hits better from the special side, which isn't boosted. And compared to Gallade, Hitmonchan not only has better defensive typing (ghost is a common attacking type, and the dark and bug resistances are useful), but it has Mach Punch. Simply put, Gallade's Shadow Sneak really can't net important KO's. It's a nonSTAB base 40 power move. Priority is so key on these sets to take out faster threats, which Gallade just can't do. Hitmonchan not only has Mach Punch but it has Iron Fist to give it a slight boost. Compare Hitmonchan's base 78 power Mach Punch priority to Gallade's base 40 priority (that several key threats, like Togekiss and Staraptor, are immune to). So although Gallade may be better at sweeping and such, Hitmonchan is the Conkeldurr of UU, and is the best pokemon for this role.