From what I have experienced in the 5 levels that ive been around.
Each time you level you get a certain number of points.
Each one of those points you have the ability to do a /cm specialization Type and then the # of points you want to put into it.
Now im not a necro so I dont know if your question is directed towards getting a necromancer response. Or if its just asking if you can put 5 into 1, 5 into the other. Which you can
You can put any # of them into the 5 options you have under /cm specialization.
It doesn't matter much which you do first, since you can max them all out. So, it depends on how you intend to play. Mana isn't normally a problem for a necro. So, I'd go for the other one.