When I am playing I treat all my secondary characters as alts, but that can change at anytime. If my main dies does that mean I just give up and let the rest of my guys die? Hell no, I swap to one of their screens, making that person the new main, and continue to give the hurtin. If I manage to escape with with the life of at least one of my guys then I can rezz everyone and keep going.

I have identical setups on all my screens so I can smoothly transition between characters with as little confusion as possible. If I am doing a quest where I need 10 snake guts then I kill them until my first character has 10, then swap to the next character and keep going until he has 10, and so. If my bags fill up with one person, I simply swap to a character with bag space and keep going.