The problem is, "jack of all trades" is not just less pretentious, it is frowned upon. What is the middle ground?

A "generalist"? A very useful person to have especially in smaller firms - you don't need a specialist in nosql databases as a CIO but an IT generalist who knows when to hire a contractor, you don't need a specialist in Delaware tax dodges as a CFO but a financial accountant who's heard of all the tricks but might not know how to implement all of them...

'generalist' + leadership skills = manager

'generalist' without leadership skills = yes man