"This leader is personally impressive" =/= great man theory. Many people are personally impressive, but they aren't lionized the in the style of great man theory. Great man theory is more along the lines of "the political whims of the masses and the goals of entrenched interests are hardly important; what really drives historical change is the occasional near-deity with almost superhuman insight and determination."

Observing that some leader is impressive within the bounds of ordinary people is fine, especially when coupled with a materialist understanding of politics. After all, materialism doesn't mean no leadership, or that leadership is purely administrative and the leaders themselves should just be any competent-enough person picked out of the crowd. Good leadership is a real skill, as is having one's life together, and respecting a leader who has both is not automatically crossing over into great man territory.