If they had cast Randy Powell and Gregory Harrison in each other's roles, the resemblance to their movie counterparts would have been significantly more pronounced. All they'd need is to bleach Randy Powell's hair.
I don't see it. Harrison was far too bland to be particularly effective in either role. Powell didn't just resemble Richard Jordan's general type -- he had a similar personality too, a sense of cold menace and sociopathic ruthlessness tempered by his friendship for Logan.
I feel the need to defend Buck Rogers. I've met both Gil Gerard and Erin Gray, and they both contend that network interference was the primary reason their show was dumbed down so much.
Oh, believe me, I'm well aware of that from my rewatch/blog reviews of the show, and the articles I found to assist me with the latter. I actually find season 1 of
Buck Rogers enjoyable, but it's superficial as hell because showrunner Bruce Lansbury explicitly wanted to avoid science fiction stories and just do "basic" TV action plots with futuristic trappings.
They've both said that if the show had made it to a third season, it would have gone back to Earth and stayed there. Buck would have done his own 'wandering the wilderness', but in the interest of bringing the peoples of the Earth together. We'll never know how well that would have worked.
I was just imagining what a hybrid of
Logan's Run and
Buck Rogers would've been like, something combining the best of both. The strong, likeable cast and understated but impressive-for-the-day gender equality of BR combined with the more SF-oriented storytelling of LR, perhaps similar to what you're describing. The original Anthony Rogers novellas by Philip Nowlan were on a post-apocalyptic Earth, after all -- although I'd be hesitant to go back there, because those novellas were horrifyingly racist tracts about the noble "White Race" heroically committing genocide against the "Yellow Peril," and the Buck Rogers comic strip was redeemed by its decision to abandon the race-war angle after its first year and instead become the first space-oriented adventure comic.
Anyway, if that's really what they had in mind, it would've been an even more massive continuity reboot than the one in season 2, since both seasons showed Earth as united. It would've basically been tossing out everything after the pilot, erasing the series proper's portrayal of Earth as a prosperous world that had many thriving cities and was a leading power in an interstellar Federation and reverting to something more like the pilot's portrayal of Earth as an impoverished wasteland with only one surviving enclave of civilization surrounded by mutant-infested ruins. It's hard to believe they ever would've gone through with such a massive revamp, even though they'd done it twice already.
Would it have worked? I doubt it, because it would've felt like a rehash of
Planet of the Apes, Logan's Run, Ark II, and
Genesis II/Planet Earth. Man, '70s TV really liked shows about post-apocalyptic wanderings. Probably because it lent itself to the kind of pseudo-anthology format that was favored at the time, since the fragmented world could be home to all sorts of isolated enclaves with whatever freaky cultures or technologies a given episode called for. That was Roddenberry's express intention behind G2/PE, and we saw it realized in
Logan's Run.