Still, the writer of this article does have some suggestions for how each should develop, and if they should happen to develop in any of the ways suggested here, it would likely bring a breath of fresh air to both characters, and probably way more mainstream love and appreciation.
Though he has been said, at times, to have the ability to have all powers of any sea animal at his disposal (ie eels' electricity, sharks' electromagnetic sense, octopus camouflage, etc), one of the main abilities he uses in combat, as far as I've seen, is his strength. He always gloats about how powerfully strong he is (and has the history to back it up, having taken on the Captain Marvel, Thor, Hulk, Hercules, etc), but never seems to put a whole heck of a lot of strategy into his combat method. Being so tough, his solution is usually just "Step 1: Hit; Step 2: Repeat Step 1 until problem is resolved".
I think that should change. I would love to see him gain more dimensions to his character and his strategy; to see him mimic the bioluminescence of a bottom-dwelling fish, to light the way for his allies on an underwater mission, or an enhanced version of a starfish's or zebrafish's regeneration, flexibility like an eel, poison generation like a blowfish, sonar/echolocation like a dolphin or whale, the stunning sonic snap of a bullet shrimp, etc--to see things like that, which actually result from situations that can't always be resolved by plain brute force, would be awesome. For a king of Atlantis, or really anywhere, we haven't really seen him as much of a strategist or a leader, so much as a warrior.
He should remain a powerhouse, but the writers should mix up what we can expect from him. Don't always make it about physical force.
As for Aquaman, he seems to have something of the opposite problem. Not the complete opposite, as of the comics from the New 52, but certainly further from the brute force end of the spectrum. In a bad way. In the old days, he was always calling on his sea critter friends to help, and his calls for help have always been for some of the most absurd reasons, in the most absurd ways.
Riding on the back of a seahorse kept us from seeing how fast Aquaman could swim on his own. Calling a gang of fish to surround the has foe kept us from seeing that Aquaman's punch packed a wallop. Getting a whale to overwhelm the attacker kept us from seeing how tough Aquaman was himself. In all, the TV and comic people of old kept having sea creatures step in for Aquaman, thus taking away from our perspective of his ability to act on his own. The comics have always tried to make him look cool, but the Super Friends show has undoubtedly been the reason his character has long been a laughingstock.
This could be easily remedied. Since Aquaman is part of a team, the Justice League, and each member has their own specialty, he's got to make his specialty (psychic powers and a supernatural weapon) stand out in a dynamic way. His trident could perhaps allow him to manipulate water (powerful, but not flooding-cities-level); it could even be summoned to hand like Thor's hammer Mjolnir. And his marine telepathy should expand from just telling sea creatures what to do--if he can see through their eyes, then his range of perception is vastly enhanced (this should extend out at least a couple miles). And his command of marine life should extend past fish--but not to the point of ANYTHING that evolved from aquatic life--it should include sea birds, alligators, etc, etc.
Though, he should only use sea animals to detect and attack foes out of reach, and should otherwise stick to his trident and his brute strength in a fight.
Though, if Aquaman would put not MORE emphasis, but BETTER emphasis on both his psychic nature and his aquatic nature, while also maintaining the improved physical prowess he's gained in the wake of the New 52, he could really stand out for what he brings to the table.
In all, we have here two Kings of Atlantis. Each deserves a chance to be respected and appreciated, as natives of the mythical Atlantis, and heroic defenders of the surface world. With the upgrades suggested above, and adequate comic/TV/movie marketing from their respective companies, these two could really start making waves as mainstream superheroes.