For a long time I have worked the guardian and I have returned to the game after leaving it and I believe that the guardian function is strictly to withstand the damage in the group but as it does little damage this form of game bores and the option is to play the Templar.
What does the company do ???? Enhance the abilities of the character that people like.
Give a single aggro option with s & s and forget the polearm and limit the game of the guardian.
It would have to create polearms with good aggro imo.
To finish I observe that it loses aggro very easily and this and some thing more has made of the guardian a game useless when not bored
Although it has good gear, AA, etc, etc ... is loose to develop its function.