So lets start off with some sets:
Electivire @ Expert Belt
Ability: Motor Drive
- Thunder Punch
- Fire Punch
- Low Kick/ Brick Break
- Signal Beam
Heracross @ Expert Belt
Ability: Guts
- Close Combat
- Megahorn
- Stone Edge
- Night Slash
For the sake of your team, I would go for Electivire. Even though it has a ground weakness like Rhyperior, Venusaur already has flying and psychic weaknesses, so Heracross will most likely prove to be a liability, even with Night Slash & Megahorn. You will need to face Lucian later, and Espeon and Alazakam will outspeed you. While you have Rhyperior for flying resistance, there's nothing on your team that has a psychic resistance/ immunity.
Bertha's Pokemon are all weak to grass or water, so as long as Venusaur and Blastoise are around you'll have no problem with her ground Pokemon.
To cover your Psychic liability, give Snorlax Crunch, and give Electivire Signal Beam. Electrivire is also able to learn Brick Break or Low Kick, which means it gives good coverage even w/o Heracross.
