I'd rather have an unproven player than a backup lineman who has started 25 games and is a senior like Josh Lugg or Kristofic.
I thought Kristofic has looked good at times?
It's generally not suggested to start underclassmen OL over upperclassmen, it's not like skill positions where speed can makeup a lack of skill in other areas like route running, etc. OL tend to take time to develop and grow into their position. There's a reason only a handful of freshmen have started there in the last few decades. They were often phenoms in their own right, but more accurately they had to fill a hole on the line due to poor past recruiting and development (See Alt, Fish, Sam Young).
If the unproven player turns out to be better than the upperclassman with experience, sure, go ahead and put them in. More often than not you're going to end up putting the guy in that has been developing 3-4 years in the system...unless they end up being really bad.