Imperial Edition units in DLC later?

I accidentaly preordered the normal version of NTW instead of the impreial edition and was wondering if I will be able to purchase the missing units later on?

More than likely they will be available for DLC a few months after release like with Empire. But if you want them that badly than I suggest fixing your pre-order.

You can always cancel your preorder.

Without a doubt. The same thing happened with etw.

It was like 6-7 months after though if I remember correctly, I would cancel that pre-order if you want the units anytime soon.