Because Medical Leave and Military Leave belong to different leave families, they must be coordinated explicitly through the Additional Leave Types field. The relationship must be configured on both leave types: Medical Leave must reference Military Leave, and Military Leave must reference Medical Leave. This reciprocal configuration ensures that units taken under either leave are counted against the balance of the other coordinated leave.
Workday does not automatically create a bidirectional relationship when one leave type references another.
Configuring only Medical Leave on Military Leave, or only Military Leave on Medical Leave, would update one entitlement calculation but not necessarily the other. The leave types must use compatible units of time so that Workday can count the coordinated units correctly.
Include all Leave Types from Leave Family is inappropriate because the two leave types are in different families. That option coordinates leave types within the same family. The related Time Off should separately be added to the Intermittent Time Offs field of the applicable leave type so its units also reduce the leave entitlement. For the specific question of coordinating the two leave types, each must reference the other through Additional Leave Types.
Reference: Workday Education - Absence for Administrators: Leave of Absence, "Coordinated Leaves and Time Off"