Think we are talking about two different things or ideas here. Or some other kind of misunderstanding.
Yes we do. And this is indented, because I have an (alternative) idea for base design, that make more sense IMHO to the Phalanx organization, the nature of alien attack patterns, and by the way heals a bunch of logic bugs.
As bishop wrote, IF the attack is an surprise (the soldiers are not regrouped) than how could they manage to evacuate the civil personnel.
And if they have time to evacuate them (without the hive mind realize what they are, and get them shot from air) than why aren't the soldiers regrouped? Then you should be able to place them where ever you want at the base (maybe by "building" the span points).
On the other Hand, IF you know before hand that the guys come, why aren't you have the base full of countermeasures? Why are all doors open within the base? Aren't there have fire control doors in the base? Why is no guy in the camera room at the beginning?
And of course, you can't loose the civil personnel, can you? If it is evacuated... than they are save, right? And why the hell, do the aliens not bombard the whole place, or flooding it with hot plasma - and even if we don't understand them... why does not AT LEAST Phalanx fear the might do or fear that they can't see them come, and planning basic base layout this way? :-)
The further advantages are:
Additional meaningful strategic decisions, risk to loose half of the base and soldiers, instead of all through if the ufo makes it to the base by bombardment, so even if you have best gear and highly trained soldiers (and good structured base) you HAVE TO fortify it, and not just let the attackers come, making it a decision to go for better aircrafts and base defense (maybe low range, high damage variants to really only defend the base).