Lit up by whom? A lot of PFs aren't offensive threats, particularly in the low post. And if he can get them to foul out on one end, they're not going to be scoring on him on the other.
I agree, it's not ideal. But I see Luke as a lot more of a shorter Dirk than I see him as a taller Chris Mullin. (Insert "poor man's" before each, of course.)
No doubt he won't get much time, unless we're beset by injuries again, but it's interesting to see that that's where he's getting played.
Personally, I think Elliot is the candidate most likely to spend time in the D-League early on, at least until a Rudy trade. Babbitt at least has value in practice - he can test the Blazers' 3-point defense. And of course Armon is our our second-best PG.