So, I hope this idea doesn't come out too stupid, but...
Maybe we can re-make the Archeon? It seems to be smaller than all the other brandish types. Combuster, Voltedge, etc are big while the Archeon is small. So we can make the size bigger to make it even.
Why? The Acheron has has a sheath that the other brandishes don't have, we don't need to make them all the same. Plus the Acheron is modeled after a katana, and having a big katana is like having a big rapier.
Like they said, it's a katana. A katana isn't that large, if Three Rings is gonna make the Archeon larger, it won't be a katana.
It's a katana. Any bigger and it'll look odd.