Fawlty Towers had just 2 series, whats your point.
And Norman Lear (and anyone who has seen both knows) openly admitted that he had to TONE DOWN the British original. Ironic, given how ‘shocking’ AITF was to US audiences.
Nobody regards FT to be in the same category as either AITF or TDDUP.
Now if you want to compare Sanford and Son with Steptoe and Son . . . (the US version had fewer seasons in this case; and I did see both)