Heracross is only a Counter if it's running a bulkier set.
Guts Boosted Earthquake versus 0 HP / 4 Def Scarf Heracross:
565 Atk vs 187 Def & 301 HP (100 Base Power): 162 - 191 / 53.82% - 63.46%
A clean 2HKO. This is assuming a Max Adamant Attack stat of 377 from CAP9 [calculated out the difference between Arceus' and Azelf's Attack stat]. ScarfHera can outspeed but obviously can only come in once.
Guts Boosted Crunch versus 0 HP / 4 Def Scarf Heracross:
565 Atk vs 187 Def & 301 HP (80 Base Power): 130 - 153 / 43.19% - 50.83%
A 2HKO with SR. With bulk, however, it's a different story.
Guts Boosted Earthquake versus 252 HP / 152 Def Adamant Bulk Up Heracross:
565 Atk vs 224 Def & 364 HP (100 Base Power): 135 - 159 / 37.09% - 43.68%
The EVs are to guarantee EQ will never 2HKO factoring SR, Sandstorm and Leftovers. Switch in on the EQ, Rest and Sleep Talk. Whatever Orb CAP9 is carrying will wear it down quickly, while, with some luck, Hera can Bulk Up and attempt an early sweep or just kill it with Megahorn. Even with no Attack investment, Megahorn is an OHKO against min HP / min Def Adamant or Jolly CAP9 (314 Atk vs 180 Def [Using Carnivine's Def Stat] & 404 HP [calculating an average between Lapras' and Lanturn's HP stat] (120 Base Power): 450 - 530 / 111.39% - 131.19%)
Guts Boosted Crunch versus 252 HP / 152 Def Adamant Bulk Up Heracross:
565 Atk vs 224 Def & 364 HP (80 Base Power): 108 - 128 / 29.67% - 35.16%
An even more advantageous situation.
An EV spread of Adamant 252 HP / 40 Atk / 152 Def / 64 Spe and a moveset of Rest / Sleep Talk / Bulk Up / Megahorn can be used to effectively Counter even the most offensive of CAP9's, assuming it's not running a Band and happens to get Burned or something improbable. And it doesn't get any stat up moves.
The 64 Speed EVs allow you to outrun 252 Tyranitar (no other useful benchmarks are met while still surviving the EQ) and the leftover 40 are dumped into Attack. They can go into SpD for extra survivability, although I've no idea what you'd be able to survive with those extra EVs.
However, one may opt to use Impish 252 HP / 32 Atk / 72 Def / 152 Spe. This will allow you the same survivability as the Adamant version but allow you to outspeed +Nature 252 Tyranitar. Some power is lost, however, but still enough to OHKO CAP9 with Megahorn, even if you dump the remaining 32 EVs into SpD.
Alas, it is not all good news ...
Guts Boosted Stone Edge versus 252 HP / 152 Def Adamant Bulk Up Heracross:
565 Atk vs 224 Def & 364 HP (100 Base Power): 181 - 213 / 49.73% - 58.52%
A 2HKO, but I'm not sure about factoring in accuracy.
Now onto Hariyama.
Guts Boosted Earthquake versus 80 HP / 252 Def Physical Tank Hariyama:
565 Atk vs 240 Def & 449 HP (100 Base Power): 253 - 298 / 56.35% - 66.37%
Guts Boosted Earthquake versus 252 HP / 252 Def Impish Hariyama:
565 Atk vs 240 Def & 492 HP (100 Base Power): 253 - 298 / 51.42% - 60.57%
Even with maxed defenses to protect against EQs, Hariyama is still 2HKO'd. Hariyama is certainly no Counter.
As for Machamp ...
Guts Boosted Earthquake versus 252 HP / 0 Def RestTalker Machamp:
565 Atk vs 196 Def & 384 HP (100 Base Power): 310 - 366 / 80.73% - 95.31%
Guts Boosted Earthquake versus 252 HP / 252 Def Impish Machamp:
565 Atk vs 284 Def & 384 HP (100 Base Power): 214 - 253 / 55.73% - 65.89%
An easy 2HKO, on both sets. Heracross' Ground resistance is paramount here.
And finally Breloom ...
Guts Boosted Earthquake versus Alternate Spread of 172 HP / 204 Def Adamant SubSeed Breloom:
565 Atk vs 247 Def & 304 HP (100 Base Power): 123 - 145 / 40.46% - 47.70%
Factoring in Poison Heal, CAP9's EQ won't 2HKO. Unfortunately, even with Max HP / Max Def, CAP9's EQ will always break Bree's Sub, so it's only option, lest it die, would be to Seed Bomb. More of a Check than a Counter.
Guts Boosted Crunch versus Alternate Spread of 172 HP / 204 Def Adamant SubSeed Breloom:
565 Atk vs 247 Def & 304 HP (80 Base Power): 98 - 116 / 32.24% - 38.16%
Just for the curious.
I should note that Life Orb boosted attacks do less than Guts boosted attacks, so their calculations are irrelevant.
I've only done calculations on Bulky Fighters, so Bulky Waters and other mentions are still on the table.
P.S. woo, first CAP post.
P.P.S if my calculations are incorrect, please disregard the rest of my statement, as I am quite tired and am prone to mistakes.
P.P.P.S if anyone can supply me the exact stats CAP9 would have in the same fashion as an analysis, that'd be greatly appreciated. I'm not sure where you guys are getting your numbers from; I'm just estimating CAP9's stats.