The trigger pulls on Glocks can be lightened, but then you are risking an AD.
All AD's can be blamed on the handler of the firearm unless the firearm is defective in some way.
The Glock was made to be safe, but it is no safer than the person using it.
Standard pull is 5.5 pounds-it can be lightened with factory parts by an armorer to 3.5-I would recommend that pull for competition only.
It can also be raised to 8 and 11.5 pounds through factory parts. Police departments use these often for liability reasons.
There is one other configuration that puts it at 6 pounds, but smooths the pull quite a bit. It's done by using the 8 pound NY Trigger spring with a 3.5 pound connector. An armorer can do it-It is not in any of the manuals-but taught in the armorers school.
I like that set up and have used it on my personal Glocks