Is It Necessary to be an Expert in "X" to be a Qualified Manager of People that Do "X"
I've spent several years in software development, using many different languages/technologies.  Now as I want to advance in my career, it seems most companies that I would want to work for desire a very specialized technical pedigree - even for a manager/director level position.

I currently manage a team of 8-10 J2EE developers, but I only became involved in J2EE within the last year.  My project management track record is solid, and continues to be even with the change in technology this year.

So my question...why is it so important to potential employers that I myself have 5-7+ years experience hands-on with J2EE if I'm going to be managing people that already have those skills?  Shouldn't my project management/supervisory abilities take precedence?
Is It Necessary to be an Expert in "X" to be a Qualified Manager of People that Do "X"
===

I've spent several years in software development, using many different languages/technologies.  Now as I want to advance in my career, it seems most companies that I would want to work for desire a very specialized technical pedigree - even for a manager/director level position.

I currently manage a team of 8-10 J2EE developers, but I only became involved in J2EE within the last year.  My project management track record is solid, and continues to be even with the change in technology this year.

So my question...why is it so important to potential employers that I myself have 5-7+ years experience hands-on with J2EE if I'm going to be managing people that already have those skills?  Shouldn't my project management/supervisory abilities take precedence?