ok, how about this. We can make it easier by only having three stats. Offensive power, defensive power and speed. Your defensive power is basically your health and your vitality. At level 1 they have whatever starting life they have and the amount of damage they take is 100 percent. Then increase defense power to level two increases their life and lowers the amount of damage they take. Offensive power is how much damage they do and speed affects being able to hit first and to dodge.
When transfering power from the reps to the leader it depends on how many reps you get power from. To make it simple we can just say that if your leader gets power from one rep then all their stats directly copy. For 2 reps you would have 2 stats from one and 1 stat from another. if you get it from 3 reps then you get the highest stat from each rep making up 3.