As good as Russell is, we have some long-ass teams here. Is a 6'9" and 6'5" front-court really gonna cut it?
Are you gonna tell mister 11 rings that he can't hang with the modern athletes?
And as far as Charles Barkley goes..he played some pretty awesome (and as long at today) competition, with way more aggressive defensive allowances, so I have no reservations that the Chuckwagon would be as good in this setting.
I think Chuck is going to be a frequent defensive liability in this setting ... but he's going to be an absolute monster in a running team. An offensive force and demon rebounder. Hugely productive and efficient.
His quickness, young Chuck's quickness and explosiveness, is going to be very hard to contain.
------------------------------------------------------
Bill Russell is going to be fine. Put him in any era and he is going to dominate.
His combination of team defense and rebounding will be the best of All-Time no matter what era or setting you stick him in. Russell's man-to-man defense will be fine. His offense is passing ability and hustle baskets mostly and those will translate well too.
There actually isn't that much elite scoring at the center position. Only really three players -- Kareem, Wilt and Shaq -- the rest are good to very good scorers but not elite. Many of whom are players who Russell could negatively effect with his defensive positioning and ability to force players away from preferred shot attempts.
Oh sorry, Olajuwon too, elite scorer. Oops. Forgot him. And on Hakeem, Russell is just about the best defender in history to stick on Hakeem though because of his combination because of his athleticism.
Looking at the list of starting centers here, I think Russell would defend Olajuwon better than every other starting center in this fantasy game. So, good news, again.
Bill Russell is going be dominant. At least, I think he'd be dominant in this setting.