Thanks for the diagram! That helps!

The fence we are trying to cover is chain link so we are hoping that
the hollies will grow through it a bit to hide it from both sides.

I read something that said if you plant them too close together that
they can develop this leggy look. Does anyone know if this is true?

We really need the bushes to merge and form a hedge as quickly as
possible, but we don't want to plant them so close together that they
don't thrive.

We're still trying to decide between Needlepoint and Nellie R Stevens.
Any thoughts? Whats the absolute closest you'd plant these type
hollies together?