Cursed field vs Gibbet? & Haunted mill vs Gallows

[Titan]

Whats the sell point of the Gibbet aside of "serve in life or in death" ? as the fields just look generally better

[Lotor13]

all building have its purpose

"the Cursed fields" is unique building chain available only in provincies with "Pastures" resource

"the Gibbet" is generic building chain available everywhere.