[@Lucidnonsense] Yes, that would be absolutely fine! We've already had a person (dereken) express interest in creating a necromancer character. Here's the link to where it was asked. Although there's not much more information added, a couple of other questions are answered there that you may find useful. http://www.roleplayerguild.com/topics/126700-empire-of-bones-fantasy-adventure-rp/ooc 
And yeah, so long as there were some differences between the two necromancers power wise, it could work well (assuming dereken still wants to make a necromancer)!