So many different things to talk about here. What is the configuration in the coop? Do you mean the two broody hens are basically in one enclosure that is totally penned off from the other flock members? Are they sharing one nest? Could you maybe post a photo? Have you given them eggs? Are the eggs due to hatch at the same time? If they are in two different nests can they get to each other's nest?
My basic philosophy with a broody hen is that she knows what she is doing a lot better than I do. So, as much as possible, I leave them alone. But how you have them set up may require some things from you. That's why I'd like to know how you have them set up.
I do not isolate my broody hens from the rest of the flock when they are incubating, hatching, or raising the chicks. The other hens can lay eggs in the broody hen's nest so I mark the eggs I want her to hatch and check under her once a day after the others have laid to remove any extra eggs. The eggs under a broody hen all need to start at the same time so they will hatch at about the same time. Otherwise you get a staggered hatch. That's where the hen has to decide to take the first chicks off the nest for food and water before the later eggs hatch.
Some broody hatches are over within 24 hours of the first egg hatching, I've had a few drag on into the third day. That's one of the frustrating things, they are not consistent. The chicks absorb the yolk before they hatch so they can go for three days or more without food or water but if they go more than that they can be in trouble. So no staggered hatches!
I never candle the eggs under a broody, it is not necessary for the eggs to hatch. I guess you could say I inspect the eggs when I check for freshly laid eggs but if a hen were isolated i would not do that. I've had hens hide nests that I did not know where they were and they hatched fine.
Before they even start to lay eggs hens add a reserve of fat to their body. This excess fat is mostly what they live off of while they are broody. That way they don't have to spend a lot of time looking for food but can remain on the nest. They still come off the nest to eat, drink, and especially go poop. They should know to not poop in the nest and mess up their eggs. I've ween a broody come off the nest twice a day and spend more than an hour off the nest each time. I'e seen a broody come off once a day for 15 minutes. Some I never see off the nest but I know they are coming off because they do not poop in their nest.
When the eggs are hatching I leave the broody alone. She knows when the hatch is over better than I do. She knows when to bring the chicks to the coop floor. How that part works for you will depend on how you have the area set up. My nests are 2 to 4 feet off the coop floor so when the hen is ready she flies down and tells the chicks to jump down to her. Since the nests are too high for the chicks to jump back up, she takes then to a corner of the coop at night to sleep.
There are plenty of people that do this totally differently than I do. I don't consider one way right and another wrong, it's just the way we choose to do it.
Some people have multiple broody hens hatching together in the same coop with different hatch dates and things go well. Some people have two or more broodies sharing one nest and co-parent with no issues. But I once had a broody attack another broody as her eggs started to hatch, wanting to take over instead of share. In the fight about half the eggs were destroyed. Anymore I don't allow two broody hens access to each others nests.