Personally, I would have liked Holy Warrior as a class and the LG Paladin as a subclass.
I have several issues with LG paladins. One is that your deity is your same or similar alignment as you, if you are a cleric. So why be lawful if you are a paragon of your deity's whims?
If your god is LE or CN, and you are an avatar of that god, you should be a champion of their ethos. So if they design Paladin with Oath of Justice to be defined as the classic LG paladin, that should be explicitly restricted to LG or LE or LN gods. But they aren't. So they're trying to achieve independence of the alignment system having any repercussions, while also trying to force a strong alignment ethos by skirting it entirely.
It is beyond stupid. If you're LG, the be an LG paladin of an LG god. If there is such a thing as a NG, CG, or LE or CE "paladin", those should be defined by appropriate subclasses where there are actual rewards for behaving in such a way. Most people who try to play LG paladins in my experience basically play them as NG or even LN, which is fine, but it's bad game design to force them to chose an inappropriately aligned subclass to your vision. Adhering to a code, any code, is a lawful endeavour. Can you even do such a thing if you a chaotic person? It's doubtful.
Paladins don't really make sense without an ethos. To have an ethos, a code, and derive benefits from it, requires a tradeoff for violating it. If you're a "barbarian" champion of the war god "Crom", you should derive your powers from any chance to wage war or settle conflicts through violence, regardless of the ultimate goal's merits. That's not the same as a LG paladin who tries to do the right thing but has to settle to the "good enough" thing because the right thing would mean they commit suicide. And no reasonable god can demand or expect that of their mortal followers. Or if they do, they should reward their faith with even better powers than some willy nilly fighter.
The entire original design of a paladin is, you trade off roleplaying restrictions for combat benefits. Many people decided this was un-fun, and wanted to have game benefits while still acting like murder hobos. To me, this means picking a CN subclass of paladin, one which is balanced vs fighters. The LG paladin should have awesome stuff, but an awesomely harsh penalty for ever even
thinking about acting like a corrupt murder hobo.
It seems that Wizards believe that their other RP aids like backgrounds or their new-fangled stuff are superior to alignment. Alignment is fairly simple, but nonetheless flexible enough to allow real growth. If you are in a group of like-minded heros, playing a palading isn't a nuisance. If you have a sadistic rogue in your group, it's beyond annoying, for the entire group including the DM. I refuse to participate in such a scenario ever again. If we have a sadistic rogue in our group, either add a CG paladin subclass who could let most things slide, or I'll just pick a different class.
Either way the alignment restrictions for paladins should have mechanical effect otherwise the entire alignment system is a waste of paper and killing trees for no good reason. Don't write rules that nobody uses, or no class or spells refer to. It's just a waste of time.
Have a coherent, consistent design vision for your game, or get off the pot and let adults who have a clue and a backbone take the helm for 6th ed. I saw a half-orc "paladin" in my last Encounters game play the most ridiculously selfish, cowardly, and non-heroic character I've ever seen, and the DM said and did nothing about it, beceause there were no rules support.
Basically 5th ed (and 4th), it's okay to murder children with your divine smite without limit because there is no way the DM can limit your abilities. Alignment is BS and has zero design space or force of effect in 5th ed.