I’m not a sociologist or a politician or a military historian, but isn’t the crux of the problem of dictators not that there’s this one guy who says “Go get all those other people!”, but that everyone else thinks “That sounds like good policy!” and not “You’re off your meds, Grandpa.”?
Also, historically-speaking, hasn’t going in with “Congratulations! We, the foreign power you’ve been propagandized against constantly, have just launched a bloody decapitating strike against your leadership! Aren’t we swell?” and then leaving lead pretty much universally to the creation of a new, more hard-line government with the express goal of getting revenge?
I’m not an expert either, but I don’t think the problem is that the population genuinely support their dictator’s policies.
Any dictator worth his salt will rapidly create an environment in which they can issue whatever goofy order they like without dissent. This is because either a) the people are scared that if they disagree, they die b) the people have little information and/or misinformation or c) both of the above.
However I agree that just taking out the guy at the top would in many cases be insufficient. In most cases, I suspect, there would either be chaos or the dictator would be succeeded by the guy he’d groomed for just that role – usually the most evil SOB.