Harris can absolutely stroke 3's. As long as we don't ask him to do much more than that I think he will fit in nicely.
If he can be what Will should have been, he'll be fine.
Sounds like another Harris we had not to long ago. 
Not really though. Lance Harris wasn't that great of a 3 point shooter (I guess I should say he was too streaky, two good years from behind the arc and two terrible years from distance), but he was pretty athletic. This kid looks like he has a really pure shot from deep, but he looks SO slow. We haven't had a 3 point specialist since...???