They weren't inevitable. As you said, he could've done the six clones or make one unique character. Now, it was impossible for all six to be unique in the given time frame.
I'm not sure if we would make that one character, though. I know it's been speculated, and whatnot, but I thought that Sakurai's mindset was all like "must beef roster! Lets add more characters!". With those "characters" being clones, of course. I'm not sure if he considered the other choice, though I imagined he probably did. Bad wording on my part.
I personally think that we wouldn't have gotten any Luigified playstyles in Brawl. The closest would be anything like Lucas or Wolf.
That's what I'm think too. Except Toon Link (and Luigi) messes everything up for me (unless if Toon Link is like a Lucas/Wolf, but with Sakurai's comments in regards to TL, I dunno...).
Considering that Falco was by far the most popular clone and is top tier, I think Roy would've held on better if he was more popular.
Yes. Falco has the luxury of being high tier AND having pre-Melee popularity and recognition (now, take a look at the Japan-bound FE6). It's just that I don't see as much hate towards other clones like Young Link, Pichu, Dr. Mario, compared to Roy (or maybe it's just me?) where ever I go. I'm more inclined to believe that perhaps Roy's obscurity in the West and tier placement are some of the causes for this. Then again, look how well Marth is treated, and he was pretty obscure at the time of Melee (just like Roy, except he got that OVA released overseas). I don't know if there were a lot of Roy detractors during Melee, that's the thing, as I wasn't around.
I'd say have more faith with the Smash 4 team on diversity though. It looks like they're trying to be more diverse with characters if Sakurai's words are any indication. Hell, just look at the first three newcomers. Miss Fit looks to be a Chun-Li like character (very fundamentals heavy with speed). Megaman's gonna be a zoning monster with those metal blades and projectiles in general. Villager looks like he'll be evil with edgeguarding once people realize to plant tress near the edge.
I understand... I'm just very skeptical when it comes to these things. They're really making a push for diversity for the newcomers, however, I hope they put some effort into the vets as well (especially the luigified ones from Brawl).
Btw, from what we know, which newcomer is the most appealing to you (and this goes for everyone else)? Mega Man's a cute little robot boy, though I think Villager's quirky and fun-looking moveset takes the cake for me.