There is already a cooldown. However that story of 5 people again'st 2-3 police officers is kinda impossible. Well I want to ask if it's fair: 1-2 guy(s) v.s 10 police officers + 4 SWAT. Well that is completely impossible to get away.
Anyways, the problem is that officers don't know how to completely RP in a bank robbery they just call S.W.A.T in and job done, but 3-2 officers can win the bank robbery against 5 guys, they just need to get vantage points and get ready, as they have a lots of space.
So yeah, it isn't unfair to the police force. And by the way S.W.A.T is always without doing nothing so I think that having Bank Robbery is their chance to get something to do (excluding raids)