With light armor and high agility, halfswording can be really effective 1v1. Part of its effectiveness is that it throws people off guard, since no one ever uses it. The animations aren't familiar to them, and they are probably expecting 2h animations when they see the sword.
Stats on halfswording mode are fine, the 2h weps that have good stabs end up with damage that rivals an ashwood pike when you thrust in halfsword mode.
They shouldn't be as good as good polearms, because a metagame that encourages polearm users to run around halfswording is just silly.