Did inadequate force to space ratio lead to the overrunning of US base in Africa?

NY Times:

Hiding in the Grass: Fear and Confusion as Fighters Overran a U.S. Airfield

The brazen Shabab assault at Manda Bay, Kenya, a sleepy seaside base near the Somali border, on Jan. 5 left three Americans dead, raising complex questions about the military’s mission in Africa.

Something as large as an airfield usually requires a number of troops to guard its perimeter.  That is not a job for a small special forces unit.  You need infantry troops to be able to patrol the perimeter and mass against assaults on the facility.  I get the impression there was an inadequate number of troops at the facility.