Remember, Arnis is pattern based. In hand to hand, you must be able to generate power to be effective, and your body must be able to tolerate generating power. This alone bumps up the training curve. Arnis is more fault-tolerant because of the weapons, and so first degree is acquired when a reasonable command of the patterns and rhythms are acquired. The International Philippine Martial Arts Federation.
Membership helps to insure minimum standards, and basic rank recognition.
Modern Arnis is an international organization with active training schools worldwide. I don't know the exact count. He has a regular seminar circuit, or you can go to the Philippines for the training camp. Kombatan is a recent name for the specific variant of Modern Arnis under GM Ernesto Presas. It is Modern Arnis.