Swampert(Relaxed)
Leftovers
-Earthquake
-Ice Beam
-Surf
-Protect
Protect is pretty useless for Swampert, besides with gaining a tiny bit of health from Leftovers, or protection from a solarbeam, which isn't very common either way. More useful would be Brick Break for better coverage, or rock slide if you want.
Camerupt(Brave)
Choice Band
-Earthquake
-Eruption
-Rock Slide
-Explosion
Eruption honestly doesn't work very well with Camerupt's low speed, as his health will probably be lowered before attacking. Flamethrower is much more reliable, and still very powerful.
Also, just a suggestion, you'll do much better in the Battle Frontier if you have a team of six, as some of the arenas will call for different types of pokemon, and those three won't always come through for you.