My personal view is that the first world is likely not the best source of flight crew anymore , as their own employment markets are quite strong , likely to only be tempted by "A List" employers in ME/Asia , and fairly skeptical about China.
Whereas taking someone from 2nd/3rd world , well in a lot of ways they have something more to play for , ie: crime at home & lower wages , & HK , Viet, etc really a much better lifestyle
Where would you find such people ?
My thinking is that you see a lot of Brazilians pilots in Asia/ME . But you seldom see many from Argentina/Chile/Peru/Colombia where many A320s are operated.
There are a few holes in your theory mate......! And this comes from one of those pilots from what you describe as crime infested and lower wages bad lifestyle "second or third world" we call it home! And you know what? It isn't that bad! LOL!
First of all....., the salary level at many airlines in Latin America is low, no doubt...., but when compared to QOL and cost....., it is still one of the highest paid with more time off gigs available.
Second...., now a days the airlines are starting to grow again and getting new airplanes...., this is causing upwards movement again with folks getting the opportunity to fly new iron, Latin America is the area with highest sales of aircrafts after Asia and with the highest growth of GDP after Asia with some countries growing at over 4% a year.
Third....., there are many of us flying on the international market..., not as many as guys from Oz, the US and Europe...., but there are many of us out here. But guess what? We just move for the higher paid contracts...., a good pilot with the experience to go for one of these gigs is not going to leave GOL or LATAM making 7 or 8 grand a month to go work at Vietnam for 10 or 12 because..., once again......, we live pretty good on the third world crime infested countries you are thinking we want to escape from
Haven said that......, Venezuela might be a source of a few bodies since their economy is in shatters and their relationship with neighboring countries is not that good..., therefore the welcome mat is not rolled out for pilot jobs necessarily. But...., another problem you will find with pilots from the region is that their English is not that good..., some might have ICAO level 4 on their licenses but their English language ability is not that good.
What I'm trying to convey here is that the LCC's are just going to have to up the ante.......!