First, the problem isn't really Spence, more the fact of him associatied with another problem guy, which makes the risk of having problems again bigger. I said the same thing for Spence and Boyd, it makes me unconfortable.
Otherwise, I don't see bigger potential in Nkemdiche than in Chris Jones, and Buckner is two floors higher than both, you can't deny that.
And I don't agree with the "above average defense stuff". You need a solid all-around defense coupled with three or four elite players. I mean, you put Miller, Ware and Harris Jr out of Denver, it's an average defense. Same goes for the Panthers.