Class Balancing ideas

Instead of limiting a user from selecting a particular character in FF via a server or map config, what if it limited the class by the number of people connected to a server?

For example, say I have a 2 engineer limit on my server. That means no matter how many people in the server, from 2 to 20, you will have access to 2 engineers per team.

But if it were limited by the number of people in the server, it could be made so if there are less than say 5 people on your team, it would only allow 1 engineer. When it hits a certain threshold, such as 6 people on the team, a 2nd engineer class could then be allowed to choose from.

Or, it could even be made so that each type of defensive class would need to be picked before selecting a 2nd type of any class. So if there's 3 people on defense, one soldier, one demo and one HW guy, before you could select soldier, demo or HW guy again, a 4th person on the team would have to choose engineer. Obviously the values could be messed around with so you could allow 2 of each class at first, but you get the point.

This would help preventing a whole team from going all engineers or all HW guys or any other class and help keep a good balance in the game.

I don't know if this is a good idea or not, but I figured it was worth mentioning. Anyway, if only 1 idea out of 100 is good, then it's worth coming up with the other 99 ideas.