With your vast experience in building walls and forts.Mamlaz said:Wooden walls were incredibly easy to build in comparison to stone walls, which is one of the reasons it took so long for stone castles to get their startup.
For a wooden wall/fort you need a 4-8 dudes and a carpenter.
For a stone structure you need an architect/mason, quarry, dozens of workers along with the issue of stone transport to the construction location.
I'd wager a stone fort could be built by 20 dudes in a matter of a couple weeks, stone forts however, months, years, often more.