Honestly its pretty spot on, consider that average people that are good at their jobs have dice pools of 6 to 8, a -3 is pretty serious. Remember most shadow runners are well into super human ranges and are effectively low level super heros.
Most street sam that are rocking their fire arms dice pools of 16+ dice are getting to the point they can try and hang with Deadshot / Bulls Eye from the comics. And for adepts or the really dedicated sams that start breaking 20+ they realistically are starting to keep company with them.