140 ATK is higher than a Pseudo's ATK.
So? at max possible attacks it only means +11 in attack stat than salamance for example, and without moves to back it up, its nothing really.
One more calc to prove it dosen't really matter, for example, earthquake fails to KO Rhydon, despite its super effective (200 power), in a minimum defense rhydon.
Only superpower would kill rhydon, yet rhydon must be minumum HP and min Defense.
This calcs done all at 140 max possible attack (max IVs and +nature) (416 attack).
If you dare to use moves like, Brick Break, its worthless, despite the stab, it won't even kill a min def electrode, so imagine starmies, gyarados, salamance coming in, with resistance and some with intimidate.
You might have tought of Mach Punch to overide that low speed, so with stab, its a 60 power move.
Well you need 4 Mach punches to kill, for example Marowak.
The only chanse of this pokemon is useing a combination of Earthquake/Mach Punch to try to score some kills on a lucky switch, or go straight to Focus Punch to do the same, hidden power ghost for ghosts (killing them if you get a lucky ghost switch in).
Ingame, Focus Punch has great PP, and it will pretty much kill all pokes that don't resist it, and maybe even some who does, yet you have to be lucky, pretty much like OHKO moves, but more PP and more fun.
You can always lower the attack if you still want to, but then it will be only a sad machamp, weaker, with nothing to do.