T-Shapes vs Jellyfish

I got a note today from my Mother- and Father-in-law about T-Shaped people. The article goes into how T-Shaped people (those with a principal 'depth' area and an inherent ability to 'branch out' into other non-related areas) naturally gravitate towards non-profits. It made me think a bit about whether the term (coined, I guess, by Tom Kelley in "The Ten Faces of Innovation" in/around 2005) is dated or is still relevant. At face value, it seems like a number of other terms I've heard around characterizing workplace dynamics (benign saboteur, terrorist, loyalist, having both breadth and depth, etc).

If one deep area is good (the arm of the T), how would you characterize a person with multiple deep areas? How would you rank the extent to which that person goes relatively more deep in any given area compared to another? It's pretty easy to rank your skills within an area (I'm an 'expert' in SQL but 'intermediate' in C#.Net and 'beginner' in AJAX) so how do you build a composite index that illustrates the relative depth of any given 'Arm'? You could spend a lot of time developing quantitative measures that will put some science around this but that's not the point of this post. What is? The fact that we should all have breadth (the bar at the top of the T) but that you should strive to 'deepen' in more than just one area. Be like a jellyfish and drop tendrils in many areas. Be a good IT professional but also understand Business Process Modeling/Management. Have some nominal capability in Organizational Leadership too.

I'm going to drop my tendrils, spread out and thrive