If you put all the Episode dividers in you can normally drag and drop the various crew members into any episode.

However if you try to drag a member of the Art section into the correct episode you cannot (except for the last one) and it just moves to the bottom of the Art section 'outside' the episodes

Of course id you do them one at a time then it works since each eisode section will be the 'Bottom one on the list as you do it, but if you make a mistake and miss one you can't add it in later.