Hi, I'm no expert, but seeing as this
plant is going to be remaining indoors, go ahead and transplant them now. It won't hurt them. But like any transplant, we bother the root systems of the
plant, so it will hold back on its growth for a bit, not long, just until it adjusts to its new environment.
As for
growing trees in a grouping or not, I prefer to keep mine separated, always. I have, as you most likely have also, seen the cause and effect of grouped
trees during growth. The weaker will die, or become diseased, which isn't good for any of the
trees in the end.
My own humble sugestion, separate them, give them each ample
growing space and they should thrive under the right conditions.
Nice find btw, to have found a bucket with 8 in it altogether!