I think a cool idea for having MA monks would be by allowing allied faction switching. Where you can switch to an allied faction at a cost of xp, gold, or something like that. So a SL monk could become an MA monk, but that SL monk could not switch to AO.
So as far as LA is concerned, any(or all three) could be true: Anyone can switch to LA, anyone in LA can switch to any other faction, or no switching to and from LA.
The fine print:
1. Only one switch ever for a character.
2. Character remains an ally of former faction, but is not a member.
3. Loses any job bonuses from former faction, and/or cannot apply for jobs in new faction.
4. Cannot have more than 5 levels in unique prestige class, or maybe even 1 level in unique prestige class.
5. Cannot have official guild tags (unless its possible to remove them from name with some server-side tool).
6. If, in the switch, the character breaks the requirement rules of the faction he's joining, the character incurs a +1 ECL for each rule broken.
So, if I'm a true neutral TC ranger, and I switch to NC, then I gain +1 to my ECL, because that alignment isn't allowed. If I happen to be drow, then my ECL is 4 (ouch). If I break two or three requirement rules, then I gain a +2 or +3 to my ECL respectively. Not sure if three requirements can be broken though... I'd have to think more about it.
So...
ECL penalties would be given for race (non gnome/dwarf switches from AO to RK), alignment, and classes.
Alternate way, if any rule is broken, a +2 ECL is incurred regardless of one or two rules broken. This alternate suggestion is dedicated to barbarian/PMs everywhere.
And btw, I'm speaking as someone who plays MA pretty much exclusively.7. Can only switch to allied faction.
8. 1 Million gold and 10% (or some percentage) xp deduction.
9. Clerics, Paladins, and Blackguards can never switch over. They are dedicated to their faction's deity. They can take their first Cleric, Paladin, or Blackguard level after they switch however (with the domain restrictions of the new faction) (So alas, no travel/trickery clerics for MA unfortunately).
10. Some sort of level requirement, like level 20 or something.
...so anyway...
As far as MA monks are concerned, they're guaranteed to be at least ECL 1 or 2 (depending on how the ECL penalties go)... so MA can have their monks, but its at a cost... and we really do want monks.
Not for PM builds cause they suck, but for relic running and such. 
