Looks like Alpenglow Graptosedum. Mine are red.

A. rufescens, maybe. And I certainly didn't know this (from Wikipedia) - 'Anacampseros L. is a genus comprising about a hundred species of small perennial succulent plants native to Southern Africa. The botanical name Anacampseros is an ancient one for herbs supposed to restore lost love.'

Since you‘re growing inside watch for etiolation. Echeveria start showing signs of etiolation fairly quickly. Just pay attention to things like the leaves flattening out, the color lightening up , and or it begins to stretch. If the lack of light goes on for too long your plant won’t revert back to it’s old look. I‘m not trying to freak you out;). If you pay attention to your plant then you can catch it early. One of the main issues I see on this forum is etiolation problems. So I’m just letting you know what to look for. Google etiolated Echeveria there are tons of pics;). Lastly, being inside this guy won’t need too much h2O because plants dry out slower inside. Maybe a good watering every 10 days or so during the hot months. Goodluck;).

Coco coir can work quite well for succulent seedlings. They are most likely G. California Sunset or G. Bronze. And they are clustering because you have given them proper conditions to reproduce as well as started with healthy leaves to propagate from. One well-off succulent leaf can produce multiple pups if given the appropriate amount of light as well as watered when roots appear. If you start caring for the pups like normal plants as soon as roots appear, the mother leaf will sometimes remain for months and continue to grow new pups. It's a fun way to add some unique multi-headed specimens to your collection. Most succulents naturally pup or offset, but when grown from a single leaf, it gives a lot of visual interest early on because many of the rosettes are of similar size/age. I quite enjoy the clustered look. You can move them around as much as you want. If you combine all of them into the same pot and want to use coco coir (which there is no problem with, you just have to water appropriately, as you said), I would honestly leave them in a smaller pot. I personally enjoy watering and in a smaller pot the water would be used/evaporate more quickly than if you chose a larger pot. Plus with less space for the roots to colonize, you would most likely see more top growth*. *this is a short-term benefit. As the roots get congested you will see a dropoff in the overall health of any plant. However, since you appear to be in Illinois, this would be something you could do for 3-4 months and watch their growth explode. I do not think this is enough time to see a detriment to the overall vitality/health of any of the plants. Then separate and repot individually in larger pots in May. This is roundabouts the ideal time for repotting most things anyway.