You can configure the drives that way, but most people would recommend against it, as the CD-ROM drives may hinder the performance of the hard drives.
The only reason to have the two CD-ROM drives on seperate IDEs, is if you are copying from one to the other. This can still be done with the current configuration, but you may need to tell your software to copy the data to the hard drive first, before copying back to the CD-RW.