During Warband of Brothers, it is possible to avoid fighting the Effigies by attacking the Hierophant from the side with purely ranged attackers.
Despite their size, they are still able to be knocked down.
Despite their name and the fact that they make Charr-like sounds upon death, testing with the Ebon Vanguard Assassin Support skill shows that these are not actually members of the Charr species for purposes of Guild Wars game mechanics. Further testing with "of Charrslaying" mods and Edge of Extinction would be needed to confirm this.