I was listening to someone recently talking about the role of steward in previous centuries. The steward managed the estate for his lord and tried to get the most return for his lord while also keeping the people of the land content.
I thought of how this is a better metaphor for those in management, and perhaps more appropriate goals than I've experienced. My experience is that most managers are simply trying their best to keep everyone happy - mainly those requesting resources (people under the manager). They are also often simply trying to make sure everyone defensibly busy.
It's in the best interest of the manager's boss, though, that resources are used for the most return. This might take some educating or a little pushing. Think in terms of how a financial advisor is both making sure your funds are being put to use, but also often educating you along the way about why he thinks you should move some of your money here or there. This would obviously help get clarity around value - the value of different initiatives, the individual strengths of the people and how to best leverage those, and helping to see that value realized as soon as practical.
Without a clear path to value back to the manager's boss, managers can be left to simply growing their department as a means of validating their value (and therefore security) in the company. But imagine this happening with your financial advisor - "I can't tell you how your funds are doing because I really have no idea, but I have some reports that show how many people report to me."