We will have to agree to disagree.
I have hunted with many paladins that followed your (or similar) make up, compared to what I proposed they seemed, for lack of a better word, frail.
Might be my perceptions on things, after all, I was playing a Paladin alongside them. sword and boarding it. But I was not impressed in the sense, that I would have been inspired to make a similar build (at the time at least).
But I will admit, the repetition of this build layout did get my attention after a while, and I have a paladin along these lines (THF, HORC), and while, yes, he can DPS impressively, I am rather underwhelmed by his AC, HP, Saves, and all around survivability, he seems rather frail compared to what I proposed.
Abet, a bit better in a solid group where he can focus on being DPS, in a haphazard PUG not so much. (At least such is my personal experience) (I need to upgrade his gear anyway, that has to be a contributing factor, but my first build was loosely outfitted at what he could get as he could get, so. in that regard they are mostly the same)
The Low Wisdom I realize was a total mistake as it dropped his will save, and that is not good, especially when that is against all the mind spells (like Hold, Charm. Ottos) and while I did not feel it until Elite Kobold Assault at 5th
it really started to hurt his overall ability to hold his own.
As for Dex, I thought Full Plate made it neigh impossible to make a reflex save.
As for the Con, issue, to get a full realization of what this means, just think of what people are willing to do for 2 more points of con, and 20 more HP the answer is obvious at how important that 2 Con is. And Con, unlike Dex, has no cap at what point it no longer becomes important to a Melee build. You can keep upping the con and it only improves the build. at 17, Dex pretty much caps off into worthless, as that is all that is needed for the feats.
In regards to Spells, I will always advocate more SP for a pally. Self heals and back up heals in pinch. survivability vs DPS, is the question in this case. In many cases, casting that extra heal spell or being able to cast remove curse resist, or even just one more Divine Favor/Zeal combo is the difference between winning and wiping. I would drop Power Attack and take Mental Toughness if the choice came down to it.
But these are just my observations from playing paladins. I am sure, everyone has their build that suits their play-style. I am not advocating that I am the authority, or that I am right . but simply this is what I have done, and played with, and witnessed in game. Like anything, take that as you will.
(I personally took the weapon focus to try and counter the Power Attack To-Hit Loss, but I can see where it is really not an optimal feat, Greater THF would be better in that case, noted)
Source please. I'd like one actually. (perhaps a few as I am always tinkering with a new pally here and there)