So I teach toddlers, and am constantly thinking about Star Wars. This is the inevitable combination of the two things that take up most of my time. If I refer to an age group, I mean in human aging, I'm not calculating for every different species.
Anyways, here are my personal head-cannons for how the Jedi creche works.
-A major factor that decides what clan a youngling goes into is their expected rate of development. There are clans for those that age at a human rate, and for those that are more long-lived. The goal is to give younglings a group of peers who will develop at a similar rate to them. (If you put a wookie child in with a group of human children, the wookie is probably going to develop some confidence issues, as all of their classmates develop faster than them).
-Most chrechemasters specialize in teaching a specific age group. There are a few who work with older children who specialize in a subject instead, but that's usually those who are teaching padawans or those old enough to be padawans. (Age 10 and up).
-In addition to teaching classes, each chrechemaster takes responsibility for a Clan (a group of younglings). They function somewhere between a counselor and a pseudo-parent, and are responsible for the general well-being of the younglings in their clan. They stay with the same clan until that clan ages out of the creche.
-Once a Clan leaves the creche, crechemasters are generally expected to stay away from their former younglings, in order to discourage attachment. That being said, most crechemasters would never turn away a former youngling in need of advice.
-Crechemasters rarely take padawans. This isn't for any particular reason, but their padawans are usually expected to also become crechemasters, so they only really take on a padawan if the youngling is about to age out and is insistent that this is what they want.
-Most creche masters are considered masters after their first Clan ages out of the creche, even if they haven't had a padawan. Raising a group of force-sensitive infants to age 10-14 is definitely a worthy equivalent of raising a padawan to knighthood, okay.
-Crechemasters rarely take missions that take them away from the temple. The exception is if they have a padawan. In this case, they tend to take a mission off planet about once a year. The idea here is to give their padawan the opportunity to learn about the galaxy in person, just as other padawans do.
-Alongside the mind healers, crechemasters have some of the most unconventional views on attachment in the Order. Most sentient children need healthy attachment in order to develop in a healthy manner. You can't spend that much time around children and not have some pretty strong views in favor of healthy attachment.
-The Senate tried to get the crechemasters to join in the war effort, insisting all hands were needed. The crechemasters threatened to leave the Order en masse if they were not going to be allowed to give the younglings the best education possible. The Senate (mostly) laid off after that.
-Soresu is a very common fighting style among crechemasters. Raising that many kids takes patience and endurance, which lends itself well to soresu mastery.