Mossbrucker will never have a strong enough leg to be a fulltime kicker. Johnie will help with kickoffs, which should help next year when we lose Murray's stronger leg. But I wouldn't be surprised if a young guy didn't come and push Mossbrucker next year.
As far as Murray's line drive form, that is actually advantagious for long kicks in cold and/or windy weather. See Adam Vinateri. But it would be nice if he could learn how to chip.
To use a golf analogy, we have one guy who can crank a two-iron, but is shaky around a green. And another guy who has a great short game, but takes too many stokes to be able to use it.
If it was me, I would enlist the help of a full time kicking coach for the next month and see if he couldn't improve either or both guys in their area of weakness.