Hello,
After a review of this, we wanted to provide an updated an fully fleshed out answer. This is also being moved to the Rules Forum for easy reference of others.
Contubernium(Squad): 1 Infantry Squad (10 Troopers), 1 BA Squad (5 BA Troopers), 1 'Mech, 1 Tank, 1 Aerospace
Century(Lance): 4-10 Infantry Squads, 5 BA Squads, 5 'Mechs, 5 Tanks (Usually 5 Contubernii, conventional infantry often different), 5 Aerospace
Maniple(Company): 8-20 Infantry Squads, 10 BA Squads, 10 'mechs, 10 Tanks (2 Centuries), 10 Aerospace
Cohort(Battalion): 24-60 Infantry Squads, 30 BA Squads, 30 'Mechs, 30 Tanks (3 Maniples), 30 Aerospace
Legion(Regiment): 72-300 Infantry Squads, 90-150 BA Squads, 90-150 'Mechs, 90-150 Tanks, 90-150 Aerospace (3-5 Cohorts)
Thank you,
Joel BC