I got thinking, about what the levels of insight would be like. Let's say for each Third Umbilical Chord the hunter gains 15 insight theoretically. With that he overpowers the Moon Presence. So as guidelines lets go with these as references. (Bold text highlights what is classed as a 'great one'.
Human infant- 0 Insight
Human adolescent- 1 insight
Human adult- 5 insight
Hunter- 8 insight
Old Hunter- 14 insight
Lesser Amygdala- 20 insight
Ebrietas- 24 insight
Amygdala- 28 insight
Celestial Emissary- 32 insight
Rom- 35 insight
Mergo's Wet Nurse- 40 insight
Moon Presence- 44 Insight
Good Hunter after three TUC's- 45 Insight
Good Hunter after defeating MP- 50 Insight

Remember this is just theoretical stuff I wasted time in my life thinking about, feel free to think of any alterations you would make.