4lb maxima to a 0.18 or 0.20 hook length will land all but the largest carp with a parabolic actioned carp.
Although the hook length is heavier in breaking strain, you will find if you get snapped it will be the hook length that will go every time due to the lack of stretch and the punishment it takes in the landing net.
If you’ve ever caught 3lb or 4lb maxima on an island you will know that it is almost impossible to snap with a rod held at 90 degrees which is why most anglers point the rod at the snag and pull for a break.