Well, I haven't faced or used that specific Medicham, but the presence of Uxie, Mesprit, and Spiritomb really hampers Medicham's performance in RU imo. I think you should note in your teammates section that it would appreciate Pokemon like Escavalier, Galavantula, or Cofagrigus to dispose such threats.
It's worth noting that Fake Out + Bullet Punch is hitting ~10% harder than CB Entei, albeit in exchange for 20% of its health. Still impressive though. Imo, HJK is non-negotiable, cuz otherwise you're really wasting Medicham's potential of wall-breaking.
As for Sigilyph, CM + Roost is certainly nice when facing more bulky teams, but against more offensive-natured teams, I find a 3rd coverage move like HP Grass or HP Ground to be really useful in preventing Pokemon like Shell Smash Omastar from setting up on Sigilyph, thus keeping the offensive pressure.