>>53357288I don't know how much can be a good limit.
Say, you have 5 objects. You can fuse them with each other, including themselves, and that should give you like 25 choices (this is just an estimated, maybe you can do more).
If you want a fusion game, you'll have to cut a lot just to reach like 500, so it's just playable and interesting.
Tring to put like up to Gen 4, is like putting 500 possible fusions, including themselves, so it's like a billion of possibilities.