SOG teams tended to travel fairly light (so you're correct there)...basic weapon was the AK or CAR-15/XM-177E2. The Hatchet Force was obviously heavier and did carry LMGs. SOG did have tons of air ordnance on call, so that to a degree offset their light organic weaponry (note that it's to a degree, but their basic mission was recon/targeting).

During Vietnam the SEALs tended to operate in teams ranging from 3-7 men, if memory serves. They had heavier weapons, in part due to their use of the Stoner system that allowed for a fairly light LMG-type weapon. SEALs didn't tend to do tons of long range patrolling, so they could go heavy on weapons and light on other stuff. Platoons tended to break into two sections for operational purposes...one "on" and one "off" if memory serves (although I could be suffering from CRS, so any corrections are appreciated).

On a related note there was a fascinating article that came out a couple of years ago (don't remember the journal title, but I do have a copy of it in the files) that involved a conference of old SOG 1-0s (team leaders) meeting with current SF personnel at Bragg. Some very interesting "compare and contrast" stuff in there, including the SOG guys feeling that they had much more control over mission planning than units do today.