I'm not a science expert, by any means
Far from it. But wouldn't the electricity from Roland (and his cohorts) be heightened and possibly kill when the Jumper is wet?
I don't want the world. I just want your half.share
Electricity doesn't get heightened or intensified when it touches water, the properties stay exactly the same. It's that water acts as a conduit for the electricity, as in it flows through the water, in the same way that it would be flowing through the cables that the paladin's shoot. So the electricity flowing through the cables would reach him in the exact same way that it would if it was flowing through water, with the same level of intensity.
Happenstance has changed my plans, so many times my heart has been outgrown