There is a great difference between street gangs &
syndicates like the mafia or yakuza. Indeed sg 'gangsters' are more
to delinquents kids rather then real gangsters. They are quite
similar compare with other countries and easily mistaken as real
gangsters.
Not all sg 'gangsters' are involved in secret society activites.
Even if they are, they are consider in the lower rank. They may
have a 'zhong', but they dun know who their real 'boss' is. (they
are not suppose to know.)
Probably these 'bosses' are running the show in Geylang... those
night clubs/ pubs, massage parlors, maybe few of the shops at lucky
plaza. 
While they are making money, do u
think they want to get involve in a fight like staring incident
caused by their 'gin nas'?
Sg too small already, no where to run... even to malaysia. In
addition, thanks to sg gov & the police using both iron fisting
& psychology warfare. Unlike local syndicate or secret
societies, overseas mafia have their own illegal businesses, also
have support from legal businesses, few even have links in
politics.
Maybe for those groups that hang out aimlessly at certain places
looking for trouble be call hooligans rather then gangters?
