Nidus is actually not very good at Arbitration. He cannot link enemies that are affected by a drone, and drone-affected enemies don't add to Mutation stacks via Virulence. You want a frame with EHP without having to interact with enemies (Chroma, Lavos, Inaros, etc).
Try to stay away from frames that require setup on enemies or wide CC; for example Nova is eh because while she has DR via Null Stars, Molecular Prime is sub-par with so many drones.