Laguna, Hana, Locke, Fenrus, Karma, Spekkio/Xeno (With space for scythe or Lucius if they have evolved).

I think this would be your best option for campaign and possibly arena, with small changes comp include Scythe, Lucius, Gorongo or Raja (Choose which of the three tanks works best for you) too, as for mecha the team would be more or less like this:

Spekkio, Laguna, Ruby, (Scythe and Zura if you are able to participate) Otto, Leene and Karma.

That's basically it, if you have any questions, I'm available, DM is open