... in the swamp, swords are resisted by almost everything,...

Uhm... No. With an iron sword (appropriate for swamps) you can slice and dice through EVERYthing very quickly. Really the only thing that is resistant to it, is Bonemass itself. Yes, blobs are easier to kill with the mace, but not by much.

Edit: I must say, that I also don't do swords until swamps or even mountains, because the atgeir is by far the best weapon for any biome. But the silver sword especially is really very useful in plains and swamps. Fighting Yagluth is a chore with Frostner, compared to the silver sword.