In the beginning, all Phantoms rookies worked in squads alongside Harvesters. Over time, their paths separated for the same reason BH-01 fighters existed.
Harvesters mostly just came to the scene after the mission was completed. Only after the Phantoms had killed all the monsters and provided safety, the Harvesters could fly to BH-01 and get to the job.
Thus, more often than not, the Phantoms only worked directly with the Harvesters when they were at K0-level.
Sometimes K1-Phantoms would do it, depending on their strength level, but K2 and stronger Phantoms just stopped working together with the Harvesters.
Sure, there wasn't some conflict or misunderstanding between these two groups, it just became technically impossible.
