Indeed, which is why I'd understand if they are included, I just don't want to see sparks happening very often. The more sparks flying in the middle of a melee, the more immersion is actually lost for anyone what has actually fought. Granted, I wasn't in a grand melee, nor was I using armor in any of the fights I was in, but I still had many scars and nicks on my blades (I can take pics to prove it).
All in all, there does need to be a visual indicator of what's going on, but like I said, there could be some recoil animations of swords bouncing off each other, and combine that with perhaps a little blade wobble (Sword blades do wobble sometimes with heavy impacts), and rarely a small spark or two, and that would be a pretty good foundation for it.
I'm not the professional, though. I'm sure I'll love whatever you guys come up with.