No... because with a smaller mana pool, you cant cast more than a couple heals in a row without running out.. regening from judgements doesnt adress this.
Actually, it kind of does. I soloed an elite this way. Every time I got low, I'd throw one or two holy lights on myself and thanks to Sheath of Light they topped off my health. Then my mana pool was low, so I judged wisdom and after two judgements my mana was topped off.
With combined mele and spell crit and the spell power from Sheath of Light, all you really need is one cast of Holy Light to top yourself off, two if it doesn't crit.
So yes you can't cast more than a couple heals without running out, but you don't really need to. And you can always judge wisdom and refill.