To be honest, I didn't find attunement mechanic enjoyable in Solasta - I found it unsatisfying to find a fun item, only not to use it, cause my 3 slots are taken by more reliably useful items. I am also not sure if limiting amount of magical artifacts per character would really do much. I don't think characters need much combos to become OP. The game is just designed that way. The philosophy seems to be that you should click at anything, and a cool think will happen. Careful character building or tactics just aren't the focus.
