Let’s assume standard BO is 26+2(+2) and fast feudal is 19+9(+2) (after this, I will ignore the scout)
Now I want to look at gathered res between vill 18 finished and the upclick to castle.
25+2(+2)=
150s *1vill + 125s *1vill + 100s *1vill + 75s *1vill + 50s *1vill + 25s *1vill + 0s * 1vill (FEUDAL CLICK) 130s * 25vills (FEUDAL REACH) + 50s * 2vill + 25s * 1vill + 0s * 1vill = 3850 villiager working seconds
18+9(+2) =
(FEUDAL CLICK) 130s * 18vills (FEUDAL REACH) + 225s * 2vills + 200s * 1vill + 175s * 1vill + 150s * 1vill + 125s * 1vill + 100s * 1vill + 75s * 1vill + 50s * 1vill + 25s * 1vill + 0s * 1vill = 3690 villiager working seconds
This means that 25+2(+2) is gathering more resources than 18+9(+2).
This ignoring that you can get eco upgrades in feudal though.
If you can afford 18+9(+2) AND get the wood upgrade early feudal (and maybe even the farm upgrade), you gather more resources.