With the level upgrade and skill point transfer, learning the skills gives an immediate increment in the summoning doll level / skill point pools. Having your paladin learn these will simply add more to the current values.
I would guess the extra radius skill probably adds to the base value stored somewhere, so having your hero learn it would probably stack with the previous levels. I didn't try that, however (I left extra skill points in the summoning doll pool, and had the skeleton learn the radius skill in the after game BF). If you get to the after game BF and your dolls keep the same range, then you should be able to increase it by having someone invest more skill points.
