Having seen both Iceman and Angels, I don't think Denzel can really compete with the Angels cast. I enjoyed his performance, but it didn't feel unique either to Hickey or Denzel, truth be told. Garfield, though, is just goddamn electric and uses every tool in his arsenal to perfect the role of Prior. I would truly be shocked if Garfield lost at all, but even more so if he lost to Denzel.
I'm confused about Angels's Olivier performance too, really, but it is a pretty American play. Given that and the timing of its revival, I think it's altogether more poignant to American crowds at this moment in time, further bolstering Garfield's chances.
In my heart of hearts, I want for Lane, Garfield, Gough, and Brown to sweep the categories but I'm not gonna hold my breath on that one.