Puede utilizar la siguiente consulta:
SELECT person_name, follower_name, cnt
FROM (
SELECT person_name, follower_name, cnt,
@rn := IF(@pname = person_name, @rn + 1,
IF(@pname := person_name, 1, 1)) AS rn
FROM (
SELECT t3.name AS person_name, t4.name AS follower_name, t2.cnt
FROM followers AS t1
JOIN (
SELECT person_id, COUNT(*) AS cnt
FROM followers
GROUP BY person_id
) AS t2 ON t1.follower_person_id = t2.person_id
JOIN person AS t3 ON t1.person_id = t3.id
JOIN person AS t4 ON t1.follower_person_id = t4.id
) AS x
CROSS JOIN (SELECT @rn := 0, @pname := '') AS vars
ORDER BY person_name, cnt DESC) AS v
wHERE v.rn = 1;
Salida:
person_name follower_name cnt
--------------------------------
John Rohn 3
Veronica Rohn 3
Ali John 2
Rohn Ali 2
La consulta utiliza variables para obtener el mayor registro por grupo.
