To me Smith just looks unfit. Overweight even. Not bulked up like Hall, just plain fat. I didn't think of him as the quickest player, but I never considered him to be slow. Now I do.
I think it's a general problem with the team too. Look at Web, and Danny McGuire. I realise they have had major injuries, but I'd also say they've both taken a strong liking to grub/drunk that doesn't help their performance, if you know what I mean?
Of course, this is just my opinion.