The whole thing about Genesect being broken is BS. He's easily checked by Heatran, who resists every single one of his moves and his immune to Flamethrower, and is also checked pretty nice by Scarfed Latios with HP Fire.
Anyways, really nice sand team! If you want a replacement for Breloom that plays similar roles, you could opt for a Substitute SD Virizion
. It does lack priority and power off the bat like Breloom, however after one SD his power nearly surpasses Breloom and when behind a Substitute, it can be downright deadly. It has the same STABS as Breloom, and finds it quite easy to come into Pokes like Blissey and Politoad to set up a Sub and attempt a sweep. Lastly, it's MUCH faster then Breloom with a Jolly Nature, and has very nice Specially Defensive bulk to go along with it.
Virizion @ Life Orb/Leftovers
EVs: 20 HP / 252 Atk / 232 Spd
- Leaf Blade
- Close Combat
- Swords Dance
Virizion now being in UU, may seem like a bad Pokemon in OU, but with the proper chance to set up, Virizion can truly destroy it's foes and out speed many threats. Also, if you don't like Substitute, you could also opt for Stone Edge or a Hidden Power
of your choice, preferably Ice
Hope this helped stir up an idea. Good luck!