The question about this deal is: why? Twaddle seems to be another Robert Dunn-esque player, better on the wing or in midfield rather than an out and out striker. He managed less than 10 appearances at Hearts last season because he was injured. We've already taken a gamble bringing McKnight back, and now we are going to sign someone else who isn't really a striker!
If we're going to sign two strikers and a right back as well as Twaddle then fair enough. If not, it's time to worry!