This is a tricky one, and mostly my position on it at the moment is "it's too early to tell." I'm not precisely happy with how this is working yet, either, but I think more needs to be done with other aspects of the game before I'll be able to make it substantially better than it now is.
We're giving more health than mana potions intentionally at the moment because we want mana to be in a lot of senses more scarce -- if you can just cook off the high level spells and then restore your mana every 10 seconds, that's going to be a huge problem.
Whereas with health if you have a ton of potions/scrolls you still can't just stay alive forever, because if you're getting killed more frequently than every 15 seconds or so it doesn't matter how many potions you have -- and unlike with mana, you can't just wait out that cooldown period, usually.
So the general rule of thumb I've been using is that it doesn't really matter how many healing potions you have, and we don't want to make it too tedious to get a goodly number of them, while at the same time you can definitely have too many mana potions, but you can definitely also have too few; the goal is having it be limited, but not survival horror limited.