Scale urgency of healing (i.e. determining prayer order) with total HP
One of the more frustrating things is not getting healed by your god when you are actually very low on HP
In certain cases, one needs 'urgent' healing, but it does not qualify as this according to the game, and you get things like removing darkness instead. This can commonly be encountered when fighting the dark druid, when characters don't have too much HP and the dark druid can hit quite hard. A character with 50% health and 50 HP is as in dire need of a character with 20% health and 200 HP, for instance. If the percentage that qualified as needing healing was scaled with total HP (somehow), it would make this much less of a problem.