I have two points to make here-
Machamp is not a good tech in SPs, sure it MIGHT help in mirror but it is clunky and has only one good attack that you will probably use(Take Out, Hurricane punch is NOT good). It also is weak to psychic so in Mirror it easy for Uxie X/Toxicroak G PL to KO you. The preferred choice would be Donphan because it is a FAST stage one, that goes with the deck(earthquake 60 for one, KO Luxray, then heal with Garchomp C LV.X) so if you want to get a fighting go with Donphan, it is less likely to be KO'd immediately(by any deck really) and is faster and less clunky, sure 4 retreat cost is painful but you would likely run warp energy with him, similar to the DGX tech.
Now onto my second point-
Yamato.
He played(i believe) a 1-1-1 Gardevoir line(IDK if he ran the x so spare me that okay?) The kirlia was the main thing in that line, played as a quick mewtwo counter. The ralts is also useful with Future sight, the gardevoir was JUST an add-on and would be great to get a drawing supporter or an extra cyrus's, think in mirror he gets AT LEAST 5 Cyrus to your 4. It was a consistency card. He also wouldn't have to add an extra energy type because he probably played Promocroak. It also can Power Lock your opponett which is very useful. So there is no comparison
Now onto why there isn't
Machop vs. Ralts, Machop has two cruddy attacks, but has HP advantage. Ralts has Future Sight, a great setup attack and an attack that can potentially stall. Ralts wins
Machoke vs. Kirlia, Machoke again has two okayish/bad attacks. Kirlia can kill mewtwo. Kirlia can win.
Machamp vs. Gardevoir, Machamp has more HP and one good attack. Gardevoir also has just one good attack. Both CAN be gamebreaking but Take Out is USELESS against stage one/two decks and PLOX can stop powers. So the attacks are about even, you could go either way. Now Gardevoir has a great thing called Telepass, one it can draw out power sprays and despite being a stage two makes the deck MAYBE a tad more consistent, Machamp doesn't. Therefore Gardevoir wins.
Gardevoir line 3. Machamp line 0.