You were quite lucky in that video for the Cobra you were stalking to collide with the other ship, taking out the shields and most of the hull - if that hadn't happened how would you have rated your chances?
I'd already committed to taking him on before the collision - turned off silent running and deployed hardpoints. So I'd say 50-50 fighting a Cobra already in combat with another Cobra around Aulin Enterprise (where my Sidewinder had the maneuverability advantage).
This was during the Aulin Apocalypse by the way, I'd already took Cobras on head to head in a Sidey and won some, lost some, during that battle.
Back to the vid, I think bounty hunting is about striking when the target least expects it - using stealth and tactics. Just steaming in head to head all the time without trying different approaches gets old fast.