"trion" juggernaut isnt = to cyttorak at all. it wasnt even because of cyttorak that "juggernaut" was that powerful. it was an outside influence keeping cains mind from controling the power, while somebody else possessed his body, and tapped deeper into the power than cain marko did. juggernaut/cain marko has the ability to do that, he just doesnt tap into his powers at such extreme levels.
8th day juggernaut appeared in an issue of thor, and it is a misconception to think he was any more powerful than regular juggernaut. historically juggernaut grows/shrinks with the amount of power that he gains/loses. that juggernaut appeared at normal size. also, he was still cain marko in possession of the power, but he "heard the call" and was trying to get to it. if anything it was a less powerful juggernaut because he was distracted and not concerned with fighting. but that is about the ONLY difference between the 2.