Of course you can!
There are MANY Bluegrass Fiddlers that use a 5-string Fiddle - obviously some Viola envy going on! 🤣😎
You might be interested in this video of Bluegrass Licks. Even though it's fiddle, NO E string involved - so you can slow this down, watch & play these licks on the Viola, exactly the same way.
OR, maybe just start with a little Bluegrass play-along exercise on the G, D & A string - with Christian Howes.