How about a Job Management Panel accompanying this Squad Management Panel?
This panel could be as simple as a list of structures (thinking of a format that looks like MS Access) in one column and the name(s) of squad member(s) working at this structure in the 2nd column, with structures that have nobody assigned to them listing 'None'.
This panel could even incorporate a bunch of nifty features such as:
- Clicking on structure name selects the structure and double-clicking centers the camera
Clicking the char's name next to the structure's name selects that character and double-clicking centers the camera
Dragging-n-dropping character portraits from the Squad Panel to the Job Panel assigns that character to work at designated structure