I appreciate the effort of this post, but it still doesn't satisfy the question. I think what happened is that everyone feels awkward about these mechanical things and orbs moving around and this only would have seemed to work if this 'mechamancing' if I'm spelling it correctly, was an element of the rp to begin with. I think where the disjunction is, is that sci-fi fantasy generally happens in the future where beings have achieved space flight and they have degraded in culture or economics back to medieval wear etc etc. 

While Leonardo davinci did make machines and a literal mechanical lion for the king, Leonardo's designs were not at the level of ...your characters'. He was a genius, but he worked with what they had at the time. 

That and our characters would just call your abberitions summons. Beings who are born with a purpose to serve their masters. 

Grafts again, seem like summoned monsters. Perhaps a blood necromancer created them. (My own terminology) who does much of the very same thing, but uses magic to manipulate the body. 

I have no idea about spelljamming, it doesn't seem to make sense to call it that since...it's a form of space travel? There are no crafts or space ships or cities that the beings of our characters could hope to create that could make space travel. I don't think they have even thought of that yet and they have no reason to go outside their planet right now because the fight is on the planet. Not on Planet X. If the reason to go outside the planet is to do satellite imaging or some strategical methods, they could do that again, with summoned beings and scouts. 

I'm not one for D&D. I know nothing about it. But the only way I can see this working is if your characters use the knowledge of the times and the materials of the times.