Why are mid tier British tanks ranked so much higher than superior US Tanks with a lower rank?

I play a lot of Rank IV stuff British and US. I often wonder why the devs rate the British tanks so much higher than the US counterparts? Example, the US T34 is 6.7 but the British Centurion III is 7.7. The US T34 has vastly better armour, a 1 hit kill gun, good AA capability and 6 crew. The Centurion has a good gun but rarely gets a 1 hit kill, often taking 3+ hits to kill incapacitate something, it has poor armour, useless AA, and other than the crude image stabilizer, its a much worse tank (I find anyway), it just has a higher rate of fire, which it needs as it rarely 1 hit kills.

Same with the Carnarvon and the FV4202, they are ok tanks but the US tanks like the T26-E1 and the T-26-E5 are a lower ranked but superior (IMO). Better armour, better guns, the British tanks are not rubbish but I see no reason why they are 7.7 when the equivalent and often
better US tanks are 6.7.
I attached a screenshot, my FV is ranked higher than the 2 US tanks in the shot but I personally think the US tanks are much better.

There is a technology that is not modern but very famous, it is called “stabilized cannon”, with a cannon like this you can shoot with the tank running, imagine how those tanks worked in 6.0 like the fv4202 or the centurions in 6.7 against tigers or panthers… … it was very fun, I remember playing fv4202 when it was in 6.0, I had 80% wins, three losses per battle.