Fire Emblem Fates: Birthright - Pairing up is not as beneficial as it was in Awakening. Since you only get the extra attack when you are on adjacent tiles and not paired-up, the only benefit is the small stat increases and protection of extra attacks from adjacent tiled enemies (which is easy to avoid if you position yourself well). I get that this is meant to be a defensive formation compared to leaving your characters on adjacent tiles in a more offensive formation, but the cost of a lot of offense since you lose the ability for an dual attack as well as lose one character turn. In Awakening, there was a real choice about pairing up since it increases the chance of a dual attack but at the cost of a character turn. Not to mention the fact that unpairing also costs a turn (now on two characters).