I do want to point out that the Fist of Rhalgr were an order of monks out of Gyr Abania that were commonly associated with Ala Mhigo. That order is no more; it was wiped out shortly prior to the Empire invading, conquering, and annexing Ala Mhigo. For any character to be considered a disciple of the Fist, they'd have to be middle-aged and have been present in Gyr Abania roughly twenty cycles (years) ago in order to have been trained by the Fist.
Erik specifically refers to Widargelt as a "monk of Ala Mhigo". Widargelt refers to himself as a "brother of the monkhood" and states that his "order is the Fist of Rhalgr". He later speaks "of the monkhood and the Fist." There's a clear distinction there.
All war-priests and disciples of the Fist of Rhalgr were monks, but not all monks are war-priests or disciples of the Fist of Rhalgr. It's fairly obvious from the 30-50 MNK quest dialogue that the Fist were but a single order of monks. That there are or were more orders that we are currently unaware of is quite likely, and that in itself implies that there could be monks not native to Gyr Abania or Ala Mhigo, even if they aren't known as "monks".
Erik specifically refers to Widargelt as a "monk of Ala Mhigo". Widargelt refers to himself as a "brother of the monkhood" and states that his "order is the Fist of Rhalgr". He later speaks "of the monkhood and the Fist." There's a clear distinction there.
All war-priests and disciples of the Fist of Rhalgr were monks, but not all monks are war-priests or disciples of the Fist of Rhalgr. It's fairly obvious from the 30-50 MNK quest dialogue that the Fist were but a single order of monks. That there are or were more orders that we are currently unaware of is quite likely, and that in itself implies that there could be monks not native to Gyr Abania or Ala Mhigo, even if they aren't known as "monks".