When we look at the way the forsaken are acting, we see that Rand has no need to make the shadow work against itself, they are already doing that quite nicely and have been doing it all throughout the series.

As for the DO not creating, that does make sense what with him being the bloke who apparently wants to destroy the creation. Though he is willing to "create" and work towards this particular goal. He created Shaidar Haran for example to rein in the forsaken and try to force them to work together against the light, when before they were almost fighting more between themselves than they were against Rand.

Rand might be able to cause some chaos amongst the shadow ranks through his link with Moridin maybe, but I doubt he will seriously be able to harm the DO or his cause in this particular way.

SNIP

You should also remember that there was a city that believed they should use the tactics of the shadow against the shadow. Shadar Logoth.