It is OK competitively because it learns the all three elemental punches at level 36, but there are so many better Fighting type Pokemon with much better stats and a duel type.
It has very a very high Sp. Def but no HP to back that up (which rules out tanking) but with its high Attack, 'meh' Defense and 'meh' Speed, it can be used as a Physical sweeper/staller.
So basically its all up to you to decide which Fighting type you want for your team and since there are better Fighting types like Conkledurr, Lucario etc., I doubt you'll pick Hitmonchan.
