1) This is purely dependent on your finger size, screen size & flexibility of the fingers. 2) If you have short fingers or less screen size, go for 3 finger claw. 3) If you have long fingers or a large screen size, go for 4 finger claw. Generally, it is better to use 4 finger claw setup in BGMI because you have access to multiple controls such as crouch, fire, aim/peek, prone, etc.