In this world, mages are exceptionally powerful. A single powerful mage can destroy entire armies. However, becoming a 'high-tier' mage is also very difficult, so most nations have very few 'high-tier' mages. However, some nations have discovered that by having dozens of weaker mages work together, they can achieve similar destructive results on the battlefield.
For example: A single powerful enough mage would be able to incinerate an entire army with fireballs. However, this feat can be replicated with dozens or even hundreds of less powerful mages channeling their magic together.
- Magic is exhausting, wiping out an entire army would cause a mage to become bedridden for weeks. So mages are usually only used as trump cards
- The more powerful the magic, the longer it takes to cast. Magic powerful enough to destroy an army would take hours to cast, and the mages cannot be interrupted
- Mages must stand next together in a formation in order to combine their magic most effectively
Are there any tactical reasons for a nation to send out their most powerful mages to the battlefield and risk losing them if sending dozens of more expendable and weaker mages is just as effective?