Since hell is more or less a nono, and in any mass exploring they are sort of a nono for neutrals too, effectively all hell groups have suffered a 33% reduction in healing. But I think you got one thing wrong, and that's saying bards are straight up better than healers. Apples and oranges, healers get sanc and cures, and healing sleep. Bard might be better in terms of long lasting straight up healing conditionally, due to resting while singing, low mana cost and group heals. On the other hand, healers are better at giving quick bursts of healing for a single person. Remember, since you didn't have dark pact/rejuvenate like you said, it's impossible to really compare. I think the bottom line is, you need both a bard, and a healer for a serious hell trip. A bard can keep up with steady healing, while the healer bursts out rejuvenates when someone suddenly gets hurt.