Bonds is Prologue VI of Fire Emblem: New Mystery of the Emblem.
Subjective: The following part of this article is subjective to the editor's writing. Therefore, it may not work for everyone.
Using two sturdy units to block both bridges will prevent any unit from being overwhelmed as each unit potentially fights at least two battles each (an enemy melee and ranged unit). The player must be careful about either unit destroying too many units at a time, as it will result in more battles for a unit in a single enemy phase.