Back when I was a secondary school student, there was a popular computer game, rtk2, which taught me about a turbulent period in China’s long history, and about getting other people to do your dirty work for you.
The game is based on a Chinese classic, Romance Of The Three Kingdoms, when warring nations eventually consolidated under the rule of 3 major powers, leading to the period known as the 3 kingdom period. I think. Anyway there are a few strategies that you can employ to undermine your opponent’s strength. Whichever way you do it, it is important that the instigator not let the target ruler know about this ploy, or incur great hostility. So you must do it subtlely,or be prepared for open warfare.
One strategy that I remember is the tiger and wolf strategy, whereby you encourage a strong and ambitious general in your enemy’s kingdom to stage a mutiny. The general is the wolf, and he is encouraged not to remain under his master, who is the tiger. The enemy ruler will be driven out and will be vulnerable when separated from his subordinates. You can follow up and run him into the ground, or you can make a move on the general who is still consolidating his power as the new ruler. Sometimes the other generals who are still loyal to the disposed ruler will follow him around, which means that loyalties will likely be split after the coup.
I never like this strategy in the game, because I lose a good general whom I would otherwise have like to hired under my employ. But when he becomes an enemy ruler, there is only death, I think. Never did I expect to see this ploy in office. And I can’t say I like it in real life either.
To do this in your office, talk to an ambitious executive about his incompetent boss, encourage him to bypass the boss and even to rally his subordinates against him, under the flag of the said ambitious executive, of course. When a person is hungry enough, the shadow of the scent of power will drive him to figure out the rest of the strategy and take it upon himself to upstage that boss whom he already dislike intensely. Promise him nothing, just hint that he can do a better job than his boss, and let him know how a mutiny can be staged. It is up to him to make him happen, and there is no trail leading back to yourself.