Hello Pinto, for this request I altered a team I used in RUPL week 4 vs EviGaro (replay
here).
(click for paste)
Scarf Flygon + Roserade do provide the synergy you wanted, letting Roserade come in against Water-types. Both work together to check Electric types, which is good because of how popular they are right now. Roserade has a cool tech here; it is Stun Spore > Synthesis, which lets it paralyze Crobat and Noivern to help Heracross tear teams apart.
Flame Orb Heracross is a crazy strong breaker that does have access to Knock Off, which you smartly suggested to remove Boots and help Spikes Roserade be more effective. You can also run LO Mienshao > Hera if you want to, I'd recommend trying them both out.
Metagross switches into Flying types for Hera and Rose and also sets Rocks; Rose covers bulky water-types for it. Pretty straightforward.
Volcanion gives the team a valuable Water Absorb mon and takes some of the pressure of checking Fire-types away from Scarf Flygon. It can also run Earth Power if you trust your teammates' ability to toxic Water-types -- Earth Power helps the team deal with opposing Volcanion better.
Finally, Wish Togekiss is a valuable glue that makes up for Roserade's lack of recovery. It can give Heracross / Volcanion opportunities to come in safely against Toge's Steel-type checks and gives Roserade opportunities to come in safely against Toge's Electric-type checks. It also checks Fighting-types and Noivern, both of which this team appreciates.
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The biggest weaknesses for this team are NP Togekiss [you don't have an Electric] and Volcanion [you dont have Gastro or a Dragon that resists its STABs]. versus NP Togekiss, you want to offensively pressure it, forcing it to switch into Heracross or Flygon and lose HP before it gets a chance to freely setup and attack you. versus Volcanion, you want to trade health on it with your own Volcanion or pressure with other threats; this matchup gets a lot easier if you run Earth Power on your Volc.
Enjoy!