The Seraphim are perfect and improved clones who are bound to follow IMU's orders.
The Pacifistas are perfect clone-machines, who follow their originator (Kuma)'s will, and protect his daughter.
Weevil is an imperfect clone who is doing everything in spite of his originator/father, attacking past allies and territories of his.
Each generation will teach something to the other, thus the Seraphim will rebel to IMU and follow their own will, Weevil will learn to protect WB's legacy, and the Pacifistas will use their "heart" to be less machine.