I know what I'm talking about, I had interface design as a subject in college.
As I had. Doesn't say too much theese days.
Of course a map view is more preciese in where your team members stand and from where danger occurs. And if this game would be real time strategy, I would totally agree a map is indispensable. For a turn based strategy game the map is over the top. There would be two ways to implement a map view: A permanent map, or a callable map.
If the map is permanent, like in games like starcraft, you are using much display expanse reducing the area for the main window. You are not able to do a too small map, since a map you could not recognize anything (or recognizing anything would take more efford than simply scrolling to the right position) is no good. And since maps are not common in round based strategy games many players probably won't use the map at all anyhow.
Making the map callable would make things even worse. However the action would be to call the map (pressing "m" to show the map, moving your mouse to a specific edge do drag in the map, zooming out, until the area display becomes a map), a player would have to take efford to call a map, in some implementations even his attention is dragged away from the main window (like if you press m and you see the map, instead of the main window). Scrolling around to find the desired location may prove as the prefered solution, even if it will take longer in the middle, since the player has not to change his attention.
There is a reason why a map is uncommon in turn based games and only used, if the playable area is really big (like in heroes of might and magic or civilization). And to be fair, how often did you really use the map in theese games? How often did you zoom out maximal in civ4 to see the whole world, just to zoom in in the desired location? Of theese reasons I think a map is over the top: Too much unused information and too much display area for its usefullness.
As I played Ufo Enemy unknown (Terror from the deep was not my game, though), I normally knew the relative position of each team member to each other. I knew, if I moved Joe, next to him was another XCOM-Operative to cover him, far to the north were two Operatives charging a house and 3 Operatives try to get to the ufo in the south. Even if you increase the number of operatives you will use, the action will not take place all over the map, there will be 2 to 5 spots where your people will be. Showing the relative position of your operatives may not help you distinguish between the left or the right operative charging the house far to the north, but you will get one of them, if you select one in the gui based on the information the arrows will give you and normally this will be good enough (since you normally would move both operatives charging the house one after the other). So more information is not needed and I can't imagine a more simple way to give this information to the player.
My second design combining the relative position with the position of opponents, however, is flawed, since I use the same representation for two different concepts. The directive position marker shows the relative position refering to the current selected operative, but the opponents marker shows the direction opponents are relative to the person represented by the gui button. Using the same representation for different things is confusing and should be avoided.
The same mistake is already done in the actual gui, since you use the same buttons once for selecting a operative and selecting a floor level. But since a new gui is searched in this thread this mistake is to be avoided in the future, once the new gui is implemented.