There's another idea (2 bases at the start):
For example, how would it look for the Machines:
________Rune Machines__________________________Devotion Machines
Rapid Fire________Sulfur Rain____________Tent_________Machine Mastery
Ballista__________Catapult______________Plague Tent
Defense:
Stalwart Defense - Defensive Hireling - Readiness
- Stone Skin
Resilience - Reflection - Magic Resistance
- Dodge
An interesting option. With this option, there will be a reason to develop the skills of combat machines.