There are quite a few differences actually. I can see where there might be a mix-up however. Especially with Prussian sixes, they are more serious and oneish. However, there are some key differences:
First, look at the core of each type. 1's are in the gut/instinctual center and 6's are in the head/thinking center. That means 1's have issues with anger and 6's have issues with anxiety/fear. That manifests itself in their respective outlooks on life: Ones are self-confident, controlled and independent. Sixes have no faith in themselves, they are reactive and dependent. Ones genuinely believe in their own power, they feel the strength of their convictions in their gut. However, like the other centers of each triad 3's and 9's, the six is out of touch with the other two triads, creating some sort of uncertainty. Sixes are isolated from their feeling/instinctual centers, so they lose their sense of inner knowing. Without these anchors, their minds run wild with anxiety.
People think that because counterphobics often project strength and certainty they aren't like your typical fearful, dependent sixes. But ultimately, the strength and certainty is a mask, a defense mechanism to overcome the fears inside. The counterphobic is constantly scanning for threats and bogeyman's so they can deal with and therefore quell their anxieties. But their assertive fronts are very easy to mistake for genuine internal certainty, which is why many counterphobic sixes play eights in movies.
Another distinctions between the two types are that sixes either are "at the feet or the throat" of authority, meanwhile the ones usually become the authority. Sixes hate to be the authority (The tallest blade of grass is the first to be cut), even the "strong" counterphobics. A counterphobic would always be wondering if a mutiny was afoot, and probably launching preemptive measures against these real or imagined mutineers. Paranoid, self-defeating tyrants is the picture of the unhealthy six leading. Ones instead think: I am the only one who knows how to do it properly/works hard enough/sufficiently competent/whatever, I guess I have to lead these people to get the job done properly. When they are unhealthy, they are overly rigid, critical and cold. Contrast Robespierre's leadership (six) with Nurse Ratched's (one).
Furthermore, when neither is the authority, ones are ultimately compliant and subscribe to the "right" ways of doing things. Counterphobic sixes are big-time rebels. Even when ones rebel, it looks much different. Imagine the difference between Gandhi (one) and Che Guevara (counterphobic six).
That is all I can think of right now, but I am sure there are more differences.