Are these guys the 8th Ed Grey Knights (now that Grey Knights are Silver marines)?
OK, the minimum Shining Spear Squad with Exarch and Star LAnce is under 100pts, but the base stat line of an Eldar Shining Spear Jetbike is (shall we call it) PEQ.
These new Marines (not a Marine), have jetbikes, move almost as fast (what's an inch or two between friends), hit harder, more resilient, and they're Marines (still not Marines).
Release them as an army, fine, but do it AFTER the T'au, Orks, and/or Necrons. The last thing we need are more Marines (still not a Marines).