[Silvermoth]

I don't think it'll be a good idea to have more than one character added to the Avengers, two at the most if they arrive in a pair like the Pyms.

It's not like with the X-men where you just have to show their personality quirks and powers. With the Avengers you also have to show how they got their powers and how they relate to the story. If you have Vision, Ms Marvel and Black Panther for example that's pretty complicated to explain without having everyone else fade into the background.