My idiocy! LMFAO. Slowbro cannot counter machamp!!! If you have toxic spikes set up, your opponent can just send in a choice band machamp (with guts) to absorb the toxic. He can then proceed to 2HKO slowbro with thunderpunch. And, if you choose to switch slowbro in, payback actually has a pretty good chance to OHKO!! If you don't believe me, go to metalkid's resources and do the calculations yourself.
Put that in your mouth and suck it!!