A risk in dealing for prospects instead of picks is the team we're trading with might know something about the prospect heading our way that we don't that, if we did know, we would not have traded for them. I think ADA was a good example in that he had extra baggage we weren't aware of that is hampering his ability to stick in the NHL. Stuff like this about players sometimes comes out but not always, so you have to be extra careful.
I wouldn't be surprised if Tampa saw something in either Hajek and/or Howden behind the scenes that made trading them much easier to swallow. Just speculation, but thus far neither have really been as good as billed (although they haven't really been disappointments either).
Maybe I'm overthinking it