Necrophage main quest line

Anyone else noticed that sometimes you get different quest path for necrophage? Sometimes you get the one which requires you do research razor mantible (chapter 2), after upgrading feeders, and sometimes you get one which requires you do destroy minor factions. Is there a way to choose?

I think the reward for destroying minor faction is much better. But it doesnt always trigger. Any idea why? Is there a way to force that one to trigger?