The guard to the south of SafeZone has a small range, he only covers about 15% of the safezone. The patrolling guards do attack mobs as they will go for untamed pets if they are within range. Problem with this though is the patrol guards well, they patrol the town and this leaves the safezone unprotected for 99% of the guards patrol.
I always stand close to guards when I go afk in safezones like PI because of it's poor layout of guards. Oh and actually the main reason... 90% of mir are ****ing ******s and are not to be trusted.