I'm taking my dervish through Tyria working on Protector title as well as the 100% map cleared title. First try I took my heroes with me and had Olias. I set all my heroes to guard. Only problem was I forgot I have no control over his minions and they attacked the druid guardians and I failed the bonus.
So I took three heroes again... warrior, monk and ranger. No hench. I fought my way to the bonus area and set them all to guard again. My monk healed my party from the druid guardians and healed me when I took damage fighting the scarabs that pop up. I left my heroes on guard the whole time. In a short time I had the three druids summoned and they joined the forth one ( the one activating the bonus) and they summoned the elder druid.
Just remember to set the heroes back to attack once you leave
But with a team of just heroes (no MM) its like doing ascalon missions with a full group of lv 20. Its a piece of cake.