Anarchism wouldn't' make any difference. The rich and powerful will still have the men with guns.
And the poor, who are by definition more numerous than even the praetorian class, will also have guns. If it comes to a shooting war... well, there's a reason kings don't have a lot of power anymore. 
King's had armies.
But today, the people in power have militaries with more destructive power than you could even think of.
I have often been amused by the very notion that guns alone will help people for example against their own government in the US.
France, Britain, Pakistan, India, China.
In all of those countries, I must laugh in the same manner. Germany, not so much anymore. We have problems financing our military here.
YOu see, if it was all about guns, I would agree. BUt it is about fighter planes, CX gas canisters, Special Forces, helicopters, cruise missiles, drones, tanks, paralyzing gas and so on. The disparity of power is by far greater than before. 200 years ago, people could take arms and win. Today, any government has the means to massacre them all in a strike, if they wanted to.
You can for example see Syrias Assad fail horribly at that, since he does not want western forces in his country. He could have just massacred them all with his means. We will see how that turns out...