Here's a real world example to verify
@shrimplover
I just started a new tank a little over a week ago. I started with all dry rock and new sand. I added a bottle of Bio-Spira and put fish and coral the same day. Never saw any ammonia and fish and coral seem healthy.
www.reef2reef.com
Notice that's an entire reef worth of fish on day one, with bottle bac, no ramp up time. If you stagger animals or if you lump them in, nothing changes about the disease course it'll come either way in a brand new dry start setup
What i mean about fish disease is opposite of that summary above so I'm glad you posted the clarifying question. Disease preps start before you add anything at all to the tank. Quarantine and fallow planning happen before anything is added, as the observed items come out of qt or fallow preps then they're added to the display. It's not that they go in the display first and then come back out to a hospital tank, that's too late your whole system would be infected by then.
Must read all stickies in the disease forum to plan for a disease protocol
After cycling is done you simply don't have to worry or plan for or assist in ammonia control by staggering anything, that part is set. If you add fish too fast you get disease issues not ammonia issues.