I thought he was a small country since a) He is a third-class mage. And clocktower's good mage (i.e worth their salt.) can take a country's army and win.
They are and Shirou at his element is generally stronger than them.
b) God's hand was ranked by you guys to need island+ to take one life.
Not in VSB's case:

Berserker (Fate/stay night)
Berserker is the Berserker-class Servant of Illyasviel von Einzbern during the Fifth Holy Grail War. His actual name is Heracles, the greatest hero of Greek mythology. A demigod, the son of Zeus and a mortal woman, he was plagued by rage all his life despite his exceptional skills. He became a...
His Durability as a whole is just Island level... when that would only account for Bypassing God Hand, not generally killing him(unless he's caught off guard as how Rin took off a life)
Side Note: It's ridiculous that Heracles doesn't even have his feat against Surtr here despite the fact that he legit did hold it off without assistance for a second.
c) Didn't you say Rin is at country level during HGW, and Shirou should be below her.
I think she's at Island+ and weaker than Shirou at that point(Outside of Jeweled Sword) and it's Adventures where she gets that level.