At least this is what you can do with the standard DCS modules such as A-10C, Ka-50, P-51D etc.
We just have to assume ED continues this trend.
As for choosing between 2 different vendors, I can't say how it will work, because testers have no such info.
Customers need to be able to install 2 different vendors in their DCS World.
Inherently, it must be possible to distinguish between them in the game-engine.
So IMHO, yes, it must be possible to do so otherwise the game-engine wouldn't be able to cope with the 2 different vendors.