SELECT
f1.name,
t1.name,
f2.name,
t2.name,
battle.date
FROM battle
JOIN fighters f1 ON fighter_1 = f1.id
JOIN fighters f2 ON fighter_2 = f2.id
JOIN teams t1 ON f1.team = t1.id
JOIN teams t2 ON t2.team = t2.id
WHERE
battle_id = 1
И правильная ли такая организация БД?