I fully support the nerf to logistics, intelligence, and slowdown. Mysticism and property are now good at the start. (It's nice to have your own mobile gold mine).
The only question remains regarding diplomacy. IMHO, you don't even need to change the existing coefficients, but simply add artifacts that affect diplomacy, which only work on the opponent outside of the collection. It would be logical if each of the artifacts reduced the join rate by a small percentage, 5-10%. It just doesn't seem logical that there are 3 major artifacts in the game that consume a lot of value, but essentially don't participate in the gameplay.