Yes, Leadership might be more useful should at least gain +1 meter radius per point, that might at least make it useful. But we've been saying that since the alpha and Larian has decided to ignore it.
The other Defensive Abilities aren't good either.
- Perseverance works on so few status effects, and restores so little armor that it's only worthwhile if you invest so many points into it that your damage dealing is crippled.
- Retribution deals so little retaliation damage that you also need to invest a ton of points into it, and even then it's worthless given that maxed it reflects half the damage you take, and enemies have a LOT larger HP pools than players do.
