Swordsman Archive

Ok, I look at the strategy guide like 50 times a day haha, and I still really can't figure out the difference between spin2, sweep2, and area3. Spin2 and Sweep2 are under the defense line for us, while Area3 is under the offense part. What I don't understand is that Area3 does everything Spin2 and Sweep2 do, but with more dmg. The speed mod is the same at 2.5. And the dmg on the Area3 is higher than the other two attacks with a dmg mod of 4. Area3 lowers posture+dizzy+massive dmg, while sweep just lowers posture and spin2 doesn't even give as much dmg as Area3. The only thing I see different is the HAM costs. But these numbers are so small that it doesn't even matter when using the 2 handed curved sword. When using this sword the only HAM cost you need to worry about is the action cost which is 2.5 with area3. But with sweep it's 2.25, and with spin it's 2. That's barely anything. So what I don't understand is why spin2 and sweep2 are under the defense side. Is there something that's really really useful with them, or does area3 replace all of the area attacks for swordsman? If so, I think I'd rather use Area3 and have a chance of making them fall over from dizziness when they lower posture and do more dmg as well.