I feel like Engagement, Corps and Displacement need to be a shared charge system, with normalized potency between them. One to get out, one to get in, one to use while strafing. Something like

Swordplay: Corps-A-Corps
Ability
Recast: 20s
Range: 25y
Effect: Rushes the target and delivers an attack with 200 potency. Shares recast with other Swordplay abilities.

Swordplay: Engagement
Ability
Recast: 20s
Range: 3y
Effect: Deliver an attack with 200 potency. Shares recast with other Swordplay abilities.

Swordplay: Displacement
Ability
Recast: 20s
Range: 3y
Effect: Deliver an attack with 200 potency and backstep 15y. Shares recast with other Swordplay abilities.

Improved Swordplay
Trait
Effect: Swordplay abilities gain charges, to a maximum of 2. The next Weaponskill used after Corps-A-Corps gain 150 potency.

Improved Swordplay II
Trait
Effect: Swordplay charge maximum increased to 3. The next spell used after Displacement gains 150 potency.

Improved Swordplay III
Trait
Effect: Swordplay charge maximum increased to 4. The next weaponskill or spell used after Engagement gains 150 potency.

Manafication: Grants 2 charges of Swordplay instead of refreshing current cooldown.

Improved Manafication: Grants 3 charges of Swordplay in addition to its other effects.