Defensively, it's not only fairy types , you also have a problem with flying , having 2 mons 2x weak to it and 1 4x weak. Heracross would only make it worse.
Salazzle for Infernape is the best option, it deals with fairies and reduces the flying problem.
rotom-mow for breelom complements this team quite well.
But the best option is lucario Aura sphere+flash cannon+nasty plot/calm mind+ 4th move
You'll have a potential mega, a poison immunity, the two weakness that you gain with the switch are easily covered by starmie( fighting and ground) and you will have a doggy on your team
Every team needs one!