I do not know. The only spells I use reguarly so far:
- Heal
- Wellspring (if I get it)
- Place road (at least in beta 4, not so much in beta 5 as it is useless now)
- Cloudwalk
- Pillar of flame
- Aura of Grace
- Aura of Vitality
- Natural Bounty
- Enchanted hammer
- Arcane Forge
- The last city production spell
- Tireless march
- Tutelage
- Summon ship (sometimes depending on the map)
- Blizzard (way better than fireball at least in b4)
- Firewall in place of Blizzard
- Haste
- Flame dart
Other spells I have not seen the need or they do not provide enough of an incentive to use. Why would I wan to use Warriors Might with so few spell casts during battle. Better save them for heal or flame dart.