The point with all these programs should be to “keep you whole”, I.e you are not worse off my going on the assignment.
As someone rightly pointed out, these assignments are to develop the individual rather than provide skills to a location which needs them.
Exxpkore program provides a lump sum payment before the start to help you move, your flights paid and a monthly component to bridge your current salary vs. Local market I.e a big uptick if you are moving from GBC to higher cost location. Many people live relatively frugally and save some $. You get another lump sum ahead of repatriating.