Unit battles are similar to standard ditch battles, except that the amount of teams and the amount of members on a team vary. They are distinct because teams are divided by clans, shogunates, and/or other groups. Alliances can happen before a battle; in fact, it is normally unheard of for a battle to not include an alliance before the start of Unit Battle, though grudge matches are usually held by the same moral beliefs as an honor duel.
Because the teams are split by clans/groups, one team will normally outnumbers the other team. The outnumbered team is expected to suck it up or find an alliance, as recruitment, availability, and member loyalty are outside factors to Unit Battles.