Word although sub + cc also is an option because the sub is not really necessary to stay many moves but to can't be attacked one turn so the drop isn't so bad for megacross.
I'm testing a team atm which is nearly the same than yours made of a wish-passer and tw-support. A problem for megacross is flyingspam defently so pokémon like rotom-w or zapdos work very well with it. Substitute is a great move helping megacross to hit pokémon it could not touch otherwise. I love it to setup on Gliscor because it's absolutly helpless if megacross has a sub (except acrobatic-sets, lol ..) and thats why I play enough speed for 72 Spd Gliscor.
With Rock Blast, Pin Missle and Close Combat it has a great offensive coverage but has to watch out for Aegislash. Thats why Heatran + Rotom-W + Megacross is a great core combined with a wish-passer, optimally clefable or togekiss for taking fighting moves.
Last time I laddered with this team and first subbed megacross my opponent was totally surprised followed by a ragequit only 3 rounds later where megacross OHKO'd 3 Pokémon of his slow team, haha.
That's why I run Thundurus, it can take a quick attack from a pinsir and other things and it gets access to prankster t-wave, I also run Scarf Excadrill to take out the Pinsirs, Talonflames, Char Y ect. Even though like you already know, if Hera is behind a sub, those 3 pokes will go down.
I personally love setting up a sub at the beginning on a rotom-w, since when not mega evolved he outspeeds with the little speed investment I have. They always go for will-o-wisp. I don't mega evolve right away and I basically can get up to 2 free kills. This thing's dangerous.
It's an interesting point you make with Gliscor, I personally am going to keep my spread though, cause there have been many situations where I barely live a hit due to the bulk investment I have, but it's an interesting point regardless.
I think Heatran is one of the best training partners Heracross can have to be honest. I run Vaporeon as a wish passer, with Heal Bell as well.
LOL I get you dude, yesterday I had a battle where Heracross killed of 4 pokes (Mamoswine, Gyarados, Gardevoir and Slowbro), it was so fucking awesome lol. This guy has become my fave mega. :-)
EDIT.- I meant to say TEAM partners, mixing up MMA and pokemon lol :P