On one hand, it is indeed to reduce one's own losses, after all, even with defensive formations, they wouldn't let the formation become chaotic, but some losses are still inevitable.
Plus, those guild armies that cannot withstand multi-directional attacks also have their uses; if coordinated in a united defense, with a steadfast formation at the core, they can play a very important role as well. In this way, these formations need not collapse, and the core formations won't suffer too much loss, benefiting both sides.
On the other hand, the commanded side receives protection and gains an opportunity to counterattack, naturally, the side being relied upon can receive a third of the military merits from those relying as compensation, which is very fair and reasonable.
