As long as they knit up for you at the same gauge, I don't see a problem. I think I'd make two separate swatches and wash them, since in my experience some superwash wool stretches and some doesn't--so rather than have a nasty surprise later on, check now.
"Trust the pattern!"
Time flies like an arrow, but fruit flies like a banana.
Hop aboard while we follow the cloud-covered van of knitting harmony, man!! Woooo!! --Hedgehog
IngridKH on Ravelry