The era I'm specifically describing is the mid 1980s and up.
They was known for being a force in the city and mainly in the city where the press could see their presence. But they knew who to pull that fake tough guy shit with. If they didn't have the numbers, they aint even bother to call for back up.
Think about it. How were Decepticons able to rob and violate people like that without the Angels doing shit about it? On the deuce? At the Latin Quarter? Or Union Square? Every weekend?
When dudes started rolling everywhere 20-50 deep, them red berets parted like the Red Sea.
I don't know about the co-founder, but you're right --- Sliwa was the fakest of them all.
Remember he admitted to faking his own kidnapping?
If there were six guardian angels and two people then the guardian angel would step to them. If it was 6 verses 6 Guardian Angel stay quiet. If it's 10 Guardian Angels 20 dudes Guardian Angels find a different subway stop to patrol.