[Hmmn, let him do some thinking here, because the concept of 'partners' is actually pretty dang important to him.]

I have already promised the Ninjask and Shedinja to two separate trainers. However, should I provide them with this information and give them each other's contact information, I do not believe they will have a problem with keeping the pair in touch in some manner. I am afraid that is likely the best I can do, under the circumstances.