The M8 for reconnaissance obviously, but I never really got explained as to what the M20 was used for during WW2.

Same thing I would warrant. 50 call or even unarmed, eyes out. I guess the utility part means it could also carry a few troopers or Some supplies but on the whole, same task I guess. Perhaps as it was even lighter and the 37mm wasn’t that much of an asset the M20 might even have had an edge.

Reconnaissance and security. It was found in Recon and MP units.
VR, Russ

TD units had them as well.
Dan

Some M20s had extra radios so they could function as command vehicles, it would make sense to create extra room in such a vehicle by doing away with the 37mm and turret mechanism.

Command and liaison. A lot of photos of M20s you see they're being used by senior officers as command vehicles.

A bit safer than a jeep. British armor commanders had scout cars, the M20 was in the TOE as an armored command and liaison vehicle.

The security units that had M20 also had M8 so the M20 was supposed to be assigned as command and communications.