I once saw directions for repairing a broken oar. They said to glue it back together as it is, then cut curved pieces out of either side that almost meet in the middle. The repair section then looks like an elongated hour glass. The cut away sections have to be long, to give a 1:10 (essentially scarf joint)taper. Then you cut two matching pieces to glue back in and carve the repair back to shape. The repair is oriented so the new pieces are on the tension and compresion faces, and the old joint sees only shear.

If your paddle is feathered, I dunno.

In any event, maybe the lesson should be that your paddle isn't strong enough for your needs, and it's time to get another. This repair will only restore it to original strength, and the ferrule plan will likely make it weaker.

The old paddle will look good hanging up on the wall.