Currently Infuse is in the Advanced Rescue/Intervention path in the Saint skill tree. However, both Advanced Rescue and intervention are direct healing spells (spells that give a certain amount of healing all at once), while Infuse is a heal over time spell. I think it would fit better in the Regeneration/Regenerative Cure Path, since those are both heal over time spells, which means it would have to switch places with Solemn Prayer, which I think would fit better in the Advanced Rescue/Intervention path, since it is a direct healing spell as well.

TL;DR: Swap Solemn Prayer and Infuse's positions in the Saint's skill tree to make them better fit the direct healing/regeneration paths

Screenshots added to show skill descriptions and tree paths