I should do something more productive, jeez.
PHANTOM BLOOD
8-C: Pre Deep-Pass Overdrive Jonathan, Speedwagon (via Buzzsaw Hat), William Zeppeli, Tarkus/Bruford, Dire/Straizo
8-C+: Post Deep-Pass Overdrive Jonathan, Dio Brando
BATTLE TENDENCY
8-C+: Everyone but Kars (Keep in mind the pillar men are rated as At least 8-C+, logically they should be much stronger and superior to the likes of Joseph and Straizo and DIO but through scaling they only get this far)
8-A: Ultimate Kars
STARDUST CRUSADERS
(I'm separating stands and stand users for this one)
Unknown: Midler, High Priestess (varies depending on material), Yellow Temperance, Death 13, Justice, Hanged Man, Sethan
10-C: Gray Fly (the old man), Mannish Boy, Enyaba the Hag, Anubis (as a sword he cannot logically harm someone unless they use their own strength to harm themselves using him),
10-A: Polnareff, Avdol, Kakyoin, Hol Horse, J. Geil, Rubber Soul, Devo the Cursed, Alessi, N'Doul, Hermit Purple, Iggy,(managed to physically harm Pet Shop, could tank casual hits from Vanilla Ice though he died a couple minutes later)
9-C: Pet Shop (Varies from 10-B to 9-C just like a regular falcon)
9-B: Jotaro
9-A: Horus, The Fool,
8-C: Joseph (shouldn't be too much weaker than his prime but safer to say he got slightly weaker as a result with age rather than directly scale him to his pillar men days), Magician's Red, Hierophant Green, Silver Chariot, Tower of Gray, Ebony Devil, Cream, Emperor, Geb (posed a great threat to Jotaro who has 8-C+ durability, should be a form of piercing weaponry like SC)
8-C+: Star Platinum, DIO, The World
DIAMOND IS UNBREAKABLE
Unknown: Cheap Trick, Heaven's Door, ECHOES2 (varies, really depends on what kanji he's using)
10-C: Shigekiyo/Shigechi (lmao should be self-explanatory, can't even run for very long), Stray Cat (should just be comparable to a normal cat/house plant), Bug-Eaten, Harvest, ECHOES1
10-B: Koichi (clearly not as strong as Josuke or Okuyasu, gets shit on physically in nearly every single fight)
10-A: Yukako, Okuyasu, Akira, Kira, Rohan, Yuya
9-C: Highway Star
9-B: Love Deluxe, Josuke
8-C: Killer Queen ("somewhat" matching Crazy Diamond in combat doesn't make you 8-C+, should be in the same boat as Magician's Red vs Star Platinum. Parried but never significantly harmed CD), ECHOES3 (can deal significant damage to himself via Giorno's attack reflection, has withstood blows from Killer Queen meaning he should be comparable)
8-C+: Crazy Diamond, The Hand
8-B: Red Hot Chili Pepper (technically varies with how much strength he has, but should be 8-B at his strongest)