Haha, you and I couldn't be more at odds over this roster. We seem to argue every time it comes up.
Lydon can do everything with a basketball that Nichols, Joseph, and Fair could do. They all played SF. So why can't Tyler?
Nah, you and I are usually on the same page--we just agree about a couple of things on next year's team [Gillon / White, primarily].
I don't know that I agree with your assessment about those player comparisons. Nichols was a catch and shoot guy, who didn't do much off of the bounce or creating for others. Joseph had a good handle in transition and was a threat to drive. Fair was a jack of all trades type, but who had more versatility than given credit for who could player "bigger" and sub at 4 to help the team. He always drove left, but he was a threat off of the bounce and had a tremendous mid-range game.
Lydon can definitely shoot threes. He has deep range, and looks to be a better three point threat than Fair or Joseph. I expect him to show more diversification this year, but it remains to be seen whether he can do more off of the bounce, or whether he'll be a threat to drive like either Joseph or Fair. He's a 4 who can really, really shoot. Joseph and Fair were 3's who could play up a position at 4 -- and both of these guys had complimentary games with the guys they played alongside, Joseph with Wes, Fair with Southerland. Can Lydon play down a position at 3? Is his game compatible with Roberson at 4? Not sure.
Ultimately, on this team, a lot of how I view the roster / project positions comes down to whether the player is the best fit at positions, given other players. Last year, Mali played three because he was the best option. Or rather, Gbinije would have been the best option, but Gbinije was also the best option at lead guard with Kaleb not having improved, so he shifted there and opened the door for Malichi to play 3.
On this year's team, Lydon isn't the best 3--White is. White isn't the best 2--Battle is. And Battle isn't the best 1--Gillon or arguably Howard are both better alternatives.
It comes down IMO to who starts at 4, and which player is asked to be a reserve. I'd expect that to come down to Lydon / Roberson, with one of these guys coming off the bench. If it's Lydon on the bench, he'll be in FAST, and will be a super scoring sub who will play 35+ minutes every game. If Roberson comes off the bench, not sure what to expect.