seedling roots grow straight down. once the first node appears though they will be tangled. seedling roots wont tangle because they dont grow that way
but as soon as you can move them, do it. because once the first node starts to appear, thats when you are going to get the roots growing outwards and they will tangle.
You also have way too many plants for those lights. 6 lights is enough for about 1 plant when using CFL's...