First, if you don't care about your time, then you can just grind any Pokemon to level 100 and beat the game with that.
If you do care about your time, then you should try to grind less and deal more damage each turn. When considering base power, accuracy, and STAB, high jump kick is the best way for both Pokemon to deal damage. Hitmonlee learns high jump kick at level 26 and has 120 base physical attack. Hitmonchan learns high jump kick by breeding and has 105 base physical attack. So Hitmonlee learns high jump kick more easily and deals more damage with it.
If you're not completely sure you want to use one of Tyrogue's evolutions, then I recommend Poliwrath over all 3 of them. Poliwrath is much easier to obtain, and its 95 base power STAB surf hits harder than high jump kick in a lot of situations.
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