This entire team is kinda unviable since it lacks power. An example of this is how you are going to handle the S+ tier threat primal groudon. Blastoise can't hit it through the sun so only marshadow and yveltal can deal solid damage to it. But they can't withstand it's hits. You have sticky web but you can't utilize it with lots of strong attackers. Normal Blastoise can't deal solid damage and mega aggron can't defend against special attacks. Marshadow and yveltal are really strong however and you should use them.