Like Apostate's Gauntlet, wouldn't it be cool if one showed the left hand while one showed the right? The name is the same, but the art and maybe flavour text be different.
Like Akash'bhuta's limbs, wouldn't it be cool if Mountainous Carapace showed AA and Fanatic fighting from the left in one card, and Legacy and Tachyon fighting from the right in another?
Wouldn't it be cool if AA's Vernal Sonata showed Tempest talking to 4 different animals on its 4 different copies of the card?
It would be cool, but slightly less clear and obviously more work for Adam. As long as the cards are still similar (like in the examples you mentioned), clarity shouldn't be such a big problem though.
One of the advantages to having the same art on the cards is they are easily recognizable from a distance. Having unique art for each card makes it harder to easily recognize the cards. While I think it would be cool, it would not be as effective. 
Yeah... if there was a serious advantage I think the guys at Wizards of the Coast would be rocking multiple arts to create more artificial collectability...
That said I would not mind if "left gauntlet" looked different. Is it at least inverted? I cant remember the card, but that would have been funny.
It's a neat idea, but a pain for the collectors. Comics do and make variant covers for comcis, some issues having 7 different covers. They get expensive, get difficult to track, and are not always that nice. It's not very well recieved.
I would like to have more art prints!
Also, Adam already does ALL of the art himself in a very short amount of time. Yes, it would be super cool, but I'm already whipping him to the point of exhaustion as is. Rather than do 220 arts for one expansion, 220 arts could be two expansions. Would you rather have every card with unique art, or more than one game every other year?
OR sacrifice the consistency of one artist doing every card, which makes every deck, from every expansion, fit in aesthetically. It is trully a luxury that they have such a hard working artist, who can reference himself (see the easter eggs in the newest cards), upgrade his own art (enhanced version) and produce a comic that looks like the cards.
They actually did that with commons a while back (Fallen Empires, Alliances, maybe Homelands too). Now alternate art cards are strictly promos.