Anger management, and assertiveness, aren't about letting it all hang out and running over people with your point of view, or about holding it all in and keeping it contained. The idea is to recognize your feelings and communicate what you need, feel, or want, in a way that is effective and respectful, acknowledging that the other person has needs, feelings, and wants too, and both sides have merit. You can be out of balance towards passivity or towards aggression, or mixed (passive-aggressive). Either way, that creates problems. Assertive is the secure middle ground. There's probably no such thing as too much balance. If you are out of balance, you have more to work on.