the techniques used by each trader are different, and the leverage that is appropriate to the technique will certainly be different, small and large leverage is good and bad, not better than both.
the truth is for professional traders who have been trained in discipline in maintaining MM leverage can be very profitable especially now there are some techniques that require a large enough margin of automatic leverage must also be large because basically a professional already has a limit in not to overtrade.
For beginners, leverage is very dangerous if it is too large because the beginner's habits of discipline are often ignored and skills are also not as good as professional traders, which results in improper trading skills, analysis is also not sure, finally overtrade the MC account. leverage so if the small leverage that limits overtrade is the leverage provided by the broker.