The Nu wallet already is a multi-coin client: NSR and NBT.
It would make sense to include the additional products there as well, right?
If you create additional clients, each of them needs to sync the blockchain.
I doubt that’s what users like.
And one NuDroid for all products would be easier to handle for users.
From a design/programming point of view it could make things easier, if each product had a separate application - as long as you keep the structure similar and make updating all the applications simple and straight-forward.