CDN – Using more then 4 hostnames

What will w3tc do with more then 4 hostnames for a site?

Notice in the following screenshot the first hostname is for CSS and the next 3 are for Javascript: https://www.evernote.com/shard/s56/sh/ae864c3d-39aa-4c3e-9e17-5e0a342485f8/f956f18c1eb665e9b8b909e0dcd1348e

So what happens if we add more then 4 hostnames? Is there even a benefit to adding more then 4, and if so at what point do the returns diminish (i.e. should I create one hostname for every asset on my site, or is that overkill) ?

Thanks in advance for the support.
-Chris