I know Larian isn't going to dedicate a full skill tree just for shields. The list is there to demonstrate various directions you can take with designs without the typical "taunt your enemies" type of shield skill. And if Larian decides to include multiple shield skills, well, I am not complaining.
In any case I'd say raising shield in the same vein as staff of magus is probably the simplest solution for a flavor skill that's useful and relatively easy to balance (and also for AI to take advantage of).
