That one with the very fluffy white hair is Oreocereus celsianus, it has a nickname: Old man of the Andes. It's natural habitat is in the high altitude area of South America. Let others id the other two.
It is never advisable to put them in a terrarium set-up, so if those were mine, I would maintain them in their individual containers for now; do not ever block the drain holes with rocks, always use containers with drain holes, and use grittier, coarser media when you plant them. If you do repot, do not water right away. Got to allow the plant's roots to heal and recover from the disturbance at the root level. Since they are succulents, they have enough moisture in their body to sustain them till it gets to grow newer roots to better anchor themselves. Your plants still looks quite young, and typically their root systems are shallow, so they do not need very deep containers.
I would revisit the plants again, this time next year if there is any need to repot, if you choose to leave them as is for now.
I would suggest get to know first the plant as they are right now. They would be happier outdoors, in a part sun/part shade area weather permitting. If your summers are too rainy, then make sure they are protected, or keep them indoors but by your sunniest window, ideally a south facing or west facing window.
