Yzerman won't look like such a genius when Tampa don't win the cup with McDonagh and his former farm team is flourishing with the Rangers.
The Lightning made out amazingly in that deal regardless of what happens. Miller is so much better then Namestnikov, and they gave up pick #29 and a pair of prospects that arguably aren't even in there Top 5 for a #2D.
They still have Raddysh, Katchouk, Cirelli, Joseph, Volkov, Stephens, Lipanov, and Yan. That's just the above average forward prospects. Howden was IMO there 4th best forward prospect behind Raddysh, Katchouk, and Cirelli.
That's not even mentioning Point or Gourde on the actual roster either. That trade was a trade the Bolts could easily afford and no matter what happens afterwards it's a trade that Yzerman was a genius to make because even the pieces he did give up weren't super expensive(Have a look at that trade thread, 90% of posts before the confirmed moving pieces were announced were talking about how Sergachev and/or Point had to be included if they were getting McDonagh AND Miller. He paid very little for a legit Top 6 forward(Something Namestnikov is not) who's still young, and a #2 Dman.