Well, this is an interesting idea, but my opinion is that your monologues should all be strong characters. This doesn't mean necessarily in-your-face, ranting and raving, etc., but with a very strong situation and emotional depth that shows you can portray it. This could be someone who is hurting, is painfully shy, is feeling rejected - all characteristics of "wallflowers," I suppose, but still "strong," in my opinion.
You remark that your monologues are "full of energy." That is a good thing. Remember, you only have a minute or two to show the auditors what you can do, and it probably isn't going to help you if your character isn't saying or doing much. We go to plays and movies and are thrilled with some of those quiet moments - all of the subtle emotions flowing across the eyes, all of the things we can imagine the character is thinking and struggling with - but in an audition situation you need to show a lot, fast.
If you characters are essentially different people and your monologues have different content, and meet the classical/contemporary and dramatic/comedic requirements, I'm sure your range will be quite sufficient. Just try to avoid either extreme - no yelling and screaming, and no sitting silently deep in thought, either.