I would appreciate it if Martyrdom would always give you 1-2% damage per Wound and 7-8% for each missing wound so that the max damage you can get stays the same (and for the sub talents something similar) or maybe you always count as having 1 missing wound even with full health.
Because more often than not there are matches where Martyrdom does nothing at all because you dont take that much damage and therefore it feels worthless to take. So some small constant bonus would feel better in my opinion without making it op.