I'm getting about 7 sword attacks and 1 CA per 15 - 20 seconds, so yes this is a great solution, think I will use this all the way now. All I need is 4 achievements, both Cross Assault and Cross Arts related.
Using Dennon's method your looking at about 125 matches. Not to bad really. They soon add up.
I found though that the method here is only useful for Cross Arts and Cross Assaults. So for the 4 related achievements your looking at doing this 250 matches.