They are pleo. Works best when you collect them all in the same area.
P. calis fly by the thousands, and it's always best to group them in threes to increase your chance of success. I've done this year after year and it works. By the second year the colony usually kills off all but one queen.
Is it practical to divide up the colony once they get workers?
Sure. There's a chance one or two of the queens may not be fertile or strong egg layers, or they could all be OK. I've never split them but don't see why it wouldn't work. Would wait til the colony is robust though, maybe 100 workers - split 33.3