The secondary base
Building the Navy’s Bases in World War II says a CUB was about one-fourth the size of a LION. The LION was the main fleet advance base, drawn at about the size of Pearl Harbor before the war.
The Logistics of Advance Bases prints the revised plan of 25 August 1942. CUB figures in that plan were 138 officers and 3,200 men, including one construction battalion of 22 officers and 1,071 men.
The Seabee Museum article uses the same one-fourth proportion and does not add a separate headcount for a CUB.