Doctrina Selection in Mixed Detachments

So as I've been theory crafting lists for Haloscreed, I've realized that Doctrina Selection per battle round gets a lot more complex with a mixed melee/ranged detachment, and I don't know if its worth doing.

I only fiddled with Rad Zone early on when I didn't have my sea legs, and Skitarii Hunter Cohort mostly benefits from sitting in protector the entire time.

Looking at people's ideas for Haloscreed, it seems like most are opting for mixed melee and ranged (Kastalans with Breachers or Destroyers). If that's the route you choose to go, Doctrinas seem to add a layer of complexity to positioning etc that could be difficult to track or do correctly.

I'm wondering if choosing a list like that is actually a trap, whereas doing something like mostly focusing melee but taking Disintegrators with the Ferrumite Cannon's +1 to hit big stuff would remove the choice of Doctrinas from the equation and make playing optimally easier.

What are your thoughts? If you like switching Doctrinas regularly, what are your strategies for doing so effectively?