It doesn't seem like the were targeting Khan, they were after the car by all accounts. And they were armed. Khan is just lucky none of them were carrying a shooter.
Bit easier to deal with, they still have to be in range to use it effectively. They had cosh's but couldn't land anything significant. Any idiot can pull a trigger.
I know Khan has a terrible chin but jesus ****ing christ talk about dumb criminals, Khan could have landed 6 punches flush in they're face before they had even time to blink.
I very much doubt they knew it was Khan, and criminals tend to be much dumber than your average member of the public.