Bill seems to think an effective 25,000 man army can just be created, supplied and equipped, trained, and led and paid and held together, by who and what?
Who controls them when they go rogue or start raping and pillaging, who owns them, what nation is their base, and on, and on, and on.
If running 25,000 man armies was easy, then Africa would have lots of them to rent out, and at least they would be someone’s national force rather than just 25,000 guys from God know where.
Well, if you wanted to just stamp your feet and have an army pop up, its not all that hard.
If the US were to announce that they were recruiting an Army corps of Filipinos you would have half the Philippine military (and mostly the best half) in line to volunteer. You could put together a couple of very decent light infantry divisions in a few weeks, out of the manpower of the Philippine equivalent of 10-12 (understrength) divisions. It would be useful to have a single nation and military as the source, as they will be from a single culture and will already have been trained in a compatible system, whatever its faults.
The Philippine government may not be too happy though. I guess if you went gradually and traded the men for military aid.
If you wanted a real Foreign Legion there are far more than 25K trained experienced soldiers from respectable militaries available around the world.
The source of direction and authority is the real killer here as you say.