The Iron Grenadiers are handpicked from Destro's personal bodyguards. They are the spearhead of Destro's incursions into new territory. The Iron Grenadiers, acting as agents, provocateurs, saboteurs, or outright terrorists, impel an unsuspecting country towards chaos and turmoil, thereby creating new markets for Destro's weapons where none existed before. Their pay is a percentage of gross sales.
"Imagine the slickest used car salesman you've ever met. Now imagine that he's also the trickiest accountant in the world. Got that? Try to picture what he would be like if that same guy was also a highly trained commando with expertise in explosives, small arms, and hand-to-hand combat. Top it off with the fact that no other mercenary group in the world wants them because of their history of turning on their superiors. That's what an Iron Grenadier is.