> [...] Do you think he couldn't fund and equip 100,000 mercenaries if his monopoly were threatened? [...]

In abstract, from the numbers sense (dollars), sure, your argument stands that test.

However, it does not stand the common sense test: what are said contractors going to do once the gig is over? Part of mil contracting is keeping yourself in the good graces of the sugar-daddy government to keep the funds rolling into the future when needs arise. Oh yeah, and also avoid going to prison (for reference, see Blackwater / US Contractor indemnification in Iraq).