Description for Cormyran Knight Training states:
You now use Charisma or Strength, whichever is higher, for attack and damage with shortswords, longswords, bastard swords, and greatswords.In addition, as long as your Charisma remains higher than your Strength and you are wielding one of the above weapons, you receive a bonus to the DCs of your Tactical Feats equal to 1/3 your Charisma modifier.
Regarding the sentence in bold: Does the 1/3 CHA modifier stack with the strength modifier for tactical feats? If so, is it actually working?