Long call reserves almost always get their trips assigned the day before. Occasionally you'll get the AM call for a late departure 12 hrs later. You're looking for the Goldilocks assignment - a PM evening after trips are assigned (by 4 PM) for an afternoon trip that just popped up. That's a unicorn. The next assignment that would work for you would be a regular assignment (3-4 PM) that leaves in the next afternoon. Every AM trip you wouldn't be able to get back to cover. It's unworkable. It's not an "overzealous Chief Pilot" that will fire you...it's almost any Chief Pilot that would fire you if you sit reserve and can't cover the majority of the trips you're assigned.