Three years? GCSE is from 11 to 16 years old. A level takes 2 years.
I agree with you about british tiger mums, disagree about math, math is not everything. For primary school year 3 curriculum , it covers Egyptian history, around world in 80 days ( georgraph), invaders ( Roman, saxon, viking) from my daughter' school. For math, they learned using Egyptian numbers and Roman numbers to pratise their math . That's a state school.
I observe the pushest mums are British mid class from our villiage school like you said. They push their children from all aspects