Can we measure a Leader's success by the number of loyal followers s/he is able to attract and keep, or do we need results?

The followers are not always a proof!

Results provide the real proof on one's success.

on the basis of result.

Results are more important.

You can attract loyalty of the sub-ordinates by other means but honesty, integrity and dedication is the only tool for getting results.

Leaders are supposed to deliver. Therefor, results are the main measure to their success.

Besides, you can measure the number of followers, but are they all loyal? Youn don't know

Results will have more followers!

Yes, it is a good measure.