Hahaha, I'm going to actually answer this question for an in-game team, like you wanted.
There are many, MANY, differences between an in-game team and a competitive battle. In an in-game team, EVs, IVs, and Natures don't really matter at all. Unlike competitive battling, in-game teams do better with something bulky such as Machamp, since it's inevitable that you are going to take some hits.
So if you are able to trade, go with Machamp. Here's a set you may like:
Machamp @ (Who cares? It's an in-game team. Fist Plate, Leftovers, whatever.)
Ability: No Guard (make sure your Machoke has this ability; if not, catch another one.)
EVs: Just kidding
Nature: Just kidding again
Moves (here's where it gets important):
- Dynamic Punch (FTW)
- Revenge (because it's slow anyway and DPunch lacks PP)
- Earthquake (because it's Earthquake)
- Payback (for ghosts, and maybe Psychics too. Nah, switch out if there's a Psychic type.)
If you can't trade and would like to do something else from the three, pick Mienshao. There's a reason it's in OU. Here's what I suggest:
Mienshao @ (Whatever the heck you want)
Ability: Regenerator
EVs: JK
Nature: JK
Moves:
- High Jump Kick (Powaahhh!)
- Aerial Ace/Acrobatics (Coverage)
- Drain Punch (Maybe your main attacking move)
- Fake Out (Free damage for every battle)
But let's assume for the moment that you're open to new ideas for your team. If I were you, I'd definitely pick Lucario (I have him on my team). This is a really good moveset:
Lucario @ Lucarionite
Ability: (Who cares?)
EVs: (Who cares?)
Nature: (Who cares?)
Moves:
- Close Combat
- Earthquake/Bone Rush/Dig
- Aura Sphere
- Shadow Ball
This guy can literally sweep anything. If you want a Fighting-type for your team and are open to suggestions, go with him.