Agree, I though I think Clarkson is a guy that cannot help us be a winner in the future, but may not necessarily be a negative in overall development.
With his numbers this year, I think he will have value on the trade market next year before the season and certainly at the trade deadline. Biggest negative is his terrible +/- on D. Though he was much better last year. Still not great, but enough to think his spark off the bench is worthwhile, especially if surrounded by some competent defenders.
TT is likely gone at some point next year. He keeps playing as he has this year and he'll have a lot of value as an ending deal for a playoff team. Clarkson not quite as much, though if that defense can go from atrocious to subpar, his value goes up.