It seems to me that in Explorer areas and in some open-air quests a lone toon is actually safer than in a group -- at least in a PUG. I play an Arcane Archer (currently level 7). In Cerulean Hills and Searing Heights I almost always manage to sneak up on a lone target from behind and kill it before it can react, without even using bow. With multiple opponents I can usually assess the situation, decide who to get first, use potions/buffs if needed, then take them out with arrows or backstab followed by arrows. I almost never get surprised.
Is because you are alone you may take your time.
Few times I explored with either other players or a hireling, there was no question of sneaking. It was just run along, and pull mobs from all around. Sure it was MUCH faster, but I may have taken more damage in the process. And open-air quests are worse in this regard.
The game is quite easy alone when you do not have to account fot the actions of another.
Yesterday for the first time I completed Irestone Inlet -- alone. Granted it was on Casual, but I had very limited heals with me. I spent some time sneaking along pathways, staying well away from hobgoblin camps, and eliminating patrols one by one. Most I managed to backstab with no damage to me at all. That got rid of what I think is the worst problem in Irestone -- patrols swarming you while you are busy fighting a camp. Then I would approach each camp, buff up, hit casters with Goblinoid Bane arrows, melee the rest, heal. I had no heals at all for last three camps; Yaryaar was in the last one. (I expected him to come running when ship blew up, but he did not.)
Casual you can one hit a mob... norm may take two or three, also the mob casters actually have some potency to them. The mob are weak on norm and 5x fold weaker on casual.
Anyway, a week or so ago I tried this quest on Normal with a party, and it was a disaster. All hobgoblins saw us from way off, "frontal assault" was the only tactic, and we kept dying. Certainly could have been coordinated better, but it was a PUG, and hardly anyone was talking to anyone. So I think that in open-air quests where commotion brings in swarming mobs, a sneaky loner can be more effective than a disorganized group. I will test that theory by doing Irestone Inlet again on Normal (but will bring more heals).
Inexperienced group. The hobgoblins are still under par to a PC, (a lvl 7 PC is near a god compared to them on norm) and if the mob saw you before you saw them ... may wish to evaluate your spot skill.
Party leadership and organizining a team play is an aspect upon itself... discipline and organization is a must... communication is a must and I might add if you're new to a quest you should stay pretty close.
Funny is ... many vets have taken to straight soloing everything up to raids except where they actually need someone else to pull a switch or should they need some other class to compensate for a needed task...
Any vet on a level 3-5 can clear these zones/quest you mention within a few minutes - alone or in group, if the group stays back at the entrance
, why well simply they know where everything is and have enough experience to know what thier character's ability is compared to that of the mobs. You get six vets in that quest ... split up and they'll finish it in little time.