I adore the Aliens design, but the arm blades aren't that necessary (unless they use some elbow fighting techniques...
) and the three fingers are a definite no no. Keep them long, with long nail/claws, connect the pairs even, but IMO it has to be four or six (I like what AVP 2010 did with them). Thought personally closer to Big Chaps six than the Covenant one's hand.
Just my personal preference