Actually no. I was watching an episode of "Enterprise" that took place in the Mirror Universe. Alt-Archer was looking up the files on his counterpart and was quite dismayed that his counterpart was considered a great man so he says "A great man is not a peacemaker, a great man is a conqueror!".
So i got a little curious to see what people would say about it.
And I do actually disagree with that Yoda quote. When you actually think of it, you will find out that some people would not have been great if it weren't for the opportunity to be a hero of some sort if there had been no war. Three names come to mind, Sergeant Alvin York, Audie Murphy, and MacArthur would not have been heroes if it weren't for the world wars they were in, for example.
Boudicca, Brian Boru and William Wallace would fall into that category as well...