All build orders more or less include wood for walling, if you start walling mid Feudal.
Early on wood is tight and if you wall, you will not get houses or the mill on time.
In mid Feudal all wood you spend on walling “just” means later farms.
For scout builds this means you can start (full) wall after building the stable, because from there on it’s “make a farm once you have 60 wood”.
For archer builds it’s a bit tighter due to archer production costing wood as well (and you need an early blacksmith), which is another reason why you usually prefer to smallwall with that build.