Let me tell you something, no matter how good your intelligence is or how well you trust your local law enforcement agencies, there will always be intelligence leak, irregularity in the way of conducting an operation which goes against the interests of the Intelligence agencies, which was more rift and damage than good. Hence the reason why you see countries who take their national security seriously (US fbi nsa, Russia fsb spetsnaz, Israeli shin be, etc) will have dedicated tactical sf units embedded within them autonomously to not interfere or endanger the intelligence they have and etc. These are the reasons why countries like US have dedicated sf teams like that despite having standby teams similar to nsg or more capable. When it comes to internal national security you have to look in two ways
* In law enforcement pov
* In intelligence pov
Both these things should not intermingle with each other