http://www.youtube.com/watch?v=A1w37RcCYxE
I test cut with Deva slayer, using left handed cuts, trying to do with minimal actions. Not all were successful but the successful one were shown here.

http://www.youtube.com/watch?v=PqH20vpF9Co
I used a Chinese made custom miao dao I designed and minimal action to cut. Successful through the thickest part but the blade notched at 2 places. So I stopped cutting with it and went to repair it because it was meant for a customer.

not bad.
that said it confirms what i suspected i.e most swords will do that damage

Deva slayer is really a beast cutter. I'm curious, do you ever do these things with No Dust and No Ego? Those swords are amazing.

ive been keeping one eye fixed on your website by the way, those trainers look VERY fun to use and very good though if your thinking of expanding your line, id suggest a viking style sword they have different characteristics compared to your 'standard' arming sword