Actually I think master plan does do this. If you look at a follower, in the upper right corner, you will see either a fist, or a blue square with a gold arrow on it. If you hover your mouse over that square, you will get more info.
The fist means that character is needed for specific missions. If you hover over it, it will show you what missions. Upgrade those users that are required for the missions you desire first.
The gold arrow means that character's skills are redundant, and not necessary for any missions. upgrade these losers last, or change their skills to make them more useful.