With swordsmen you get a better armour save, higher init (more likely to hit first) better ws but a little less strength, So you are more likely to survive and hurt cheap weak troops but any well armoured elite stuff will laugh at you.
With halberdiers you've got lower ws, st ,Init and very little armour for 1 pt of st against anything but dwarfs/ saurus and undead they will get splattered all over the battlefield.
With halberdiers you've got lower ws, st ,Init and very little armour for 1 pt of st against anything but dwarfs/ saurus and undead they will get splattered all over the battlefield.