Advice on transplanting required.

I'm completely new to gardening and need some advice. I've planted six cabbage and six broccoli plants and they seem to be thriving. They're planted beside potatoes which are just starting to show foliage now and they are only about two inches away from the row of thriving cabbages and broccoli which are about six inches tall. They are too close together and I don't know how this happened. Is it safe to dig up the cabbage and broccoli and transplant them further away from the potatoes ? Any advice would be greatly appreciated. Thanks in advance.