..."Not really, and probably not."
The real, and slightly more complex, answer is "Depends, but not as an overall strategy." It depends on what you've got in your Talent points, what gear you'd be swapping out to get those defensive stats, and what mobs you're facing.
Some Defense and Block Rating might make your life a little easier, especially when it comes to nudging lower level mobs along the attack table. As a Holy Paladin, you're probably not inclined to stack so much Defense and Avoidance (Block, Parry, and Dodge ratings) that you'd get a noticeable effect against even same-level mobs. So any small, incremental increase in Defense or Avoidance is only really coming into play against mobs who aren't likely to hit or crit you very hard anyway. You're pretty much just hedging your bet even more that the low-level mob won't hit you hard at all.
Now, the ability of Protection Paladins to grind against multiple, non-caster mobs is fairly legendary. The forums are alive with the tales of Protadins grinding ten, twenty, thirty or more mobs into loot-ridden paste beneath their feet. All at once. Sometimes, while away from keyboard. And it's true: Protection Paladins can do that sort of thing. It's what we're built to do, as the Superhot AE Tank.
But the synergy of a Protection Paladin's gear and their resulting ability to grind is based on a few talents in the last half of the Protection tree. Holy Shield and Blessing of Sanctuary are both must-have talents for Protadin AoE grinding. These talents make up a pretty significant portion of their damage. Every time the mob hits the Protadin, the mob takes reflective damage from Holy Shield and Blessing of Sanctuary (as well as Retribution Aura, Shield Spike, and whatever else they might have happening at the time).
Without those particular tools empowering your reflective damage, all you'd really be doing with Defense and Avoidance is missing out on the damage output of the stats you swapped out. If various pieces are weak points (not having spell crit or spell damage), then maybe replacing those pieces will help you a little bit. If the cloth isn't directly helping your damage, then why not ditch it?
But, short of relearning your talents, your best bet is probably just to work on getting better Shockadin gear. You want more damage, not more not-entirely-helpful Defense. A good shield will probably give you a little nudge, without sacrificing too many stats. Shields are fairly awesome for that.
You probably want to look at your Judge and Seal rotation -- if you have both Wisdom and Light up at the same time, that's where some of your damage is going. Try the Ye Olde Judge-Crusader, Judge-Righteous rotation. You're just going to be better off by increasing your damage, upgrading your gear, and maybe popping consumables. As a Holy Paladin, you're not going to get the big returns on Defense and Avoidance like a Protection Paladin would.