Ok, I am assuming that you have those different rings because they are in different tents or rooms? If not what if the reasoning?
What is the actual layout you are dealing with, like can you sketch up the floor plan and put measurements, or even use graph paper? I am looking to see the pathways, bends, distances...
I do highly recommend a 1 inch main line, perhaps PVC. Maybe even larger if your pump will do 1-1/4" then break off with three 1 inch lines that feed each ring/area and then reducing tees to 3/4 for sites. You want as big as you can get at the sites IMO. Using a unibit you could likely upsize the holes provided they aren't too close to the bottom of your site.
Really pictures, I need pictures lol. Show me what your system looks like and your space. I'm thinking PVC until you feed a ring, then transition to flex with a barbed fitting off the PVC. So Like 1-1/4" off the pump, reduce to three 1" take offs for each ring and put a valve there on each take off, then run the 1" PVC to the space the ring will be and transition to 1" flex for the ring and take offs with 1" to 3/4" reducing tees to the sites.
You can also put a valve on each 1 inch take off to feed a ring, use that valve to proportion/balance the flow to get things evenly distributed to each ring regardless of a little difference in distance from the pump.
Just my thoughts from what I know about the intended setup so far. If nothing else you can see my logic and figure out what you wanna use from all that mumbo jumbo I just wrote lol I am so high RN.