[GS] Archeological museum: Two artifacts from same civilization break the theming (Not a bug?)

[MightyEvilPunk]

Version: 1.0.0.341 (443561)

Behavior:

1. I have an archeological museum (Ephesus in save file)
2. I have 3 artifacts there:
   1. Longsword (Medieval - Victoria)
   2. Chalice (Medieval - Jayavarman VII)
   3. Doubloon (Renaissance - Victoria)
3. Though longsword and chalice could potentially get me "2/3 themed" results, they do not, because of doubloon
4. If I replace doubloon with any artifact, not matching in terms of era, but not belonging to either Victoria or Jayavarman VII, theming 2/3 is received