Blaziken
Possible movesets:
Fast moves:
Low Kick (fighting, 7 BP/0.6s, 6 EPU)
Ember (fire, 7 BP/0.6s, 6 EPU)
Charge moves:
Brick Break (fighting, 60 BP/1.6s, -33.3 EPU)
Flare Blitz (fire, 100 BP/2.8s, -50 EPU)
Thunder Punch (electric, 45 BP/1.8s, -33.3 EPU)
Blaziken will not overtake Machamp as the highest DPS Fighting type, but it would be much better for dodgers with the fastest fighting quick move Low Kick, and a very short duration charge move Brick Break. It's like the fighting version of DB/DC moveset. It would also be superior to Machamp against Regice and Registeel due to resisting STAB moves. But not against Regirock.
As for the fire moves, I made Ember a faster move with higher energy gain to make it not completely inferior to Fire Spin like it currently is. I made Flare Blitz a broken move (it would be the best 2 bar move) to give Blaziken (also Charizard and Flareon) a small advantage over the fire legendaries with moveset Ember or Fire Spin / Flare Blitz. Also because of fire's lack of relevance in the meta.
Answers
Blaziken has weaker stats, and Machamp moveset is already perfect. I cant imagine Machamp getting outclassed. Hariyama could be interesting case with lower attack but massive hp pool.
On the other hand, Blaziken's fire typing is quite a blessing, even if he functions as a fighting attacker. He will resist both Blissey and Snorlax best non-legacy charge moves. (Heavy Slam and Dazzling Gleam). Usable pokemon most likely, but not going to overthrow Machamp.
I just hope torchik wont be as rare as the gen 1 and 2 fire starters.
Fire is my favourite type and I always pick a fire starter in all the main series game.
But take a look at my pokedex!!
bulbasaur - 279/323
squirtle - 218/241
charmander - 87/95
chikorita - 304/408
totodile - 228/292
cyndaquil - 54/65
It took me a few months till the starter spawn event that I got my 1st charizard.
But I do hope blaziken will get both a double fire or double fighting moves so it will be usable for me.