Oddly, Holminster switch seems to be the most dangerous, probably because it's before you get back / improve your mitigation and healers get their newer healing tools. The Bears there serve as good indicators of how big your pull to should be, either killing first then pulling the rest, or using them as the stop gap for a two pack.

HS is completely doable in wall to wall, though it does seem far more stressful than the rest of them, outside the two potential mega pulls in Mt. Gulg, but if you're going for those, you probably aren't pugging.