First, you can simplify those three calls and combine them into one. This makes it more readable and efficient:
{_x addEventHandler["fired",{_this exec"TimedGrenade.sqs";_this exec"fired.sqs";_this exec"RPGdeviate.sqs"}]} forEach thislist
Secondly, try adding a delay of 1 second to that trigger, ie fill in 1 in the Max/Mid/Min fields of the trigger property dialog and see if that helps.