Imagine unloading on a boss with a offensive paradigm that features a commando (soldier) and two ravagers (black mages), then if your health is running low, you could switch to a defensive minded paradigm with a couple of medics and a sentinel (
damage sponge) to build yourself back up, and then you could use a support styled paradigm with a synergist (party stat booster) and a saboteur (
enemy stat nerfer) to help even the odds.