While rovers have made incredible discoveries, their wheels can hold them back, and erratic terrain can mean damage. There is no replacing something like Perseverance, but sometimes rovers could use a leg up, and they could get that from a small swarm of four-legged robots.
Issue there is how does it handle loose fill material or sand/dust in its joints? That’d wear it down quick or result in it getting into an unrecoverable situation. (Wheeled rovers have a larger contact area and less likely to sink into sand.)