With regards to substitute, the substitute of a flying pokemon in my mind should not sit on the ground. It would be highly obvious it was a sub, and therefore I believe that a substitute of a flying Pokemon remains airbourne.
Originally Posted by Fat Bulbapedia
In the anime, substitutes are seen to be exact clones of the user.
N.B. S_o_S, thanks for the flavour, but substitutes in AS are definitely not cardboard! :-)
The Rock Slide is less straightforward. I personally think that surround you and around you are slightly different. The slight inconsistency makes things difficult. If Archeops was to use a move that requred a line of sight between Mamo and himself, I would deifinitely go for around. Even if the rock slide is from above, there would be no way of telling (from mamo's point of view) where within the Ring he is.
I am going to rule that Rock Slide has BP 5 Against both archeops and the Rock Shield as some rocks hit each. The shield acts around
Archeops. The Shield is Rock Type, with Rank 4 Defence and Sp. Defence.
I will get S_o_S to fix this ASAP.