M2 vs Machamp with fighting moves?

Well Machamp does it faster, Mewtwo happens to last longer. So what's your priority?

Full disclosure: I have only one high-level Mewtwo, which is configured as Shadow Baller, I do not have enough candy to power up a second one, and thus I use Machamp for gym sweeping. They fall like flies, as everybody and their dogs are using defenders with Fairy attacks nowadays.

Machamp. It's not even close.

With potions as expendable as they are, and the sluggishness of focus blast, machamp is far and away the better gym clearer. Side bonus of having both counter and DP boosted in cloudy weather, whereas cloudy only boosts FB for mewtwo.

Better to keep a mewtwo at confusion/shadow ball to slot in a raid party if you run out of ideas.

I use both. The choice might depend on what else is in the gym besides Snorlax & Blissey. Sometimes the psychic quick move is useful. And Mewtwo's focus blast animation looks pretty cool.

My first Mewtwo had Confusion/Focus Blast when I caught it. I used it for a while to fight gyms. Tried C/F and P/F, prefer C/F since Confusion can deal respectable damage on its own and is not so reliant on using its full 100 energy move for damage.

Mewtwo can be useful against fully motivated Blissey or Snorlax since there will be more time to charge up and use multiple Focus Blast. Although, since I have powered up/evolved more weather boosted Machops, I have not used Focus Blast Mewtwo as much. I've been considering trying the charge TM dance to get Shadow Ball like my second Mewtwo or maybe Psychic.

If you're short on Revives/Potions, use Mewtwo. He's extremely potion efficient for it. If you've got plenty of those, just use Machamps.

Machamp is better. If you want tank, go Hariyama/Tyranitar.

I've found that Machamp does it faster than Mewtwo and I haven't noted a significant difference in fainting. Yeah, Machamp faints more often on average, but it's really more of an "R"NG thing than a serious difference in stats.

The difference is small enough that my "Fighting" team to take out Gyms is 4 Level 35 Machamps, 1 Level 35 Hariyama and 1 Level 30 Mewtwo with Psycho Cut and Focus Blast. (No real mechanical reason for the PC - I just like the animation of it.) The Mewtwo is the first one that I sub out - say there's a Vaporeon defender and I've got a Research Project to get 7 Charged Moves in Gym battles, I'll sub in something like an Eggy with Grass moves, or an Electric with 2 or 3 bar moves, just to get that Research Project done then I'll switch back to the Machamps to clear the gym down.

Really, when it comes down to it, both Machamp and FB Mewtwo are good choices for clearing out "Normal" gyms. I've got 3 Mewtwos (none with IV's above 80, none with Attack above 12, but hey - MEWTWO!!! so not complaining) and Mewtwo is NOT a game-breaker, game-changer or even much of a game-adjuster for me. It's the cherry on top, not the banana of a banana split, so to speak.

Focus Blast Mewtwo is not better Hariyama why compare him to Machamp?

I wouldn't max more than 2 to 3 machamp. hariyama, mewtwo & other pokemon can fill up the 4 to 6 spot since those spot arent use often.

Honestly, what it comes down to for me, is whether or not there are other trainers battling. I can't pass up a chance to show off my pride and joy!

If you dodge chargemoves at least 50%, nothing trumps a machamp with DP.
even on speed alone machamp wins