NASA's Perseverance Mars Rover

You're talking sense, Paul. As you say, opinions certainly differ, especially among people of different scientific disciplines (e.g. meterology vs. geology), and that even extends to the mission PIs. Steve Squyres was certainly driven and focused in achieving his science goals, which meant that the MER missions drove hard as well. John Grotzinger was criticized for not connecting the dots and "lacking focus" on a big flagship rover. From everything I've seen and heard, Ken Farley is being more careful in balancing priorities (and I'd say his job is a lot harder here, considering the needs of sample return!) All that being said, even pure geologists will certainly disagree amongst themselves, though we don't see that here as interested members of the public.

I'm not privy to the inner workings on this project by any means - certainly not directly. Having observed prior missions from a somewhat closer perspective, however, I see Mars 2020 as very, very driven by the work of other missions and a surprisingly broad community. Orbital spectroscopy and geologic mapping has guided this rover in detail from the very start, to a degree greater than I remember even for MSL, and I'm not aware of much debate about the rover's planned route at any point since before landing. I was personally quite surprised by the short amount of time that Percy spent in Neretva Vallis (amazing place!), to say nothing of acquiring only one sample. Yes, there aren't many spots as interesting as Bright Angel along the traverse path, but I still don't agree that one sample was enough, and I somehow doubt that I'm alone in that opinion.