Armiger is perfectly good Fighter Archetype IMHO
especially if you want Intimidate and Know(Planes) but don't want to give up on other skills.
(FYI Human extra Skill Ranks is great if that's priority, although anybody can get Skill Ranks via Favored Class Bonus)
Not sure what you mean by "will it hold on its own", do you mean solo adventuring?
The game really isn't built for that period, and almost any Fighter will have constrained competencies (re: healing or magic generally)
although Armiger's extra skill ranks help to cover more bases there, and items/consumables can help with magic.
Tanking is a pretty marginal concept/role in Pathfinder, although not sure how that fits in with solo-ing?
Certainly your AC and HPs can be pretty high with Heavy Armor and Fortification Enchants (Crit negation) enabled by that.
There can be lots of "high AC" or "resilient vs combat" builds, this certainly handles that area fine.
I would say Armor and Weapon Master's Handbooks Advanced Training options are good things to look at for any Fighter,
and Magic Tactics Toolbox's (Magical) Item Mastery is a good option to gain more magical tools for a Fighter.
The other thing I would note is that while the Ardent ability is perfectly good (really, better than base ability it replaces)
it does mean you won't qualify for any Feats that build on top of Bravery or have Bravery as a Pre-Req.
But it's not like there isn't a ton of other options for your Feats, including ones I mentioned :-)
Anyhelp
Perhaps I'm too late, but I'd like to direct you to the following post that may help.
https://www.reddit.com/r/Pathfinder_RPG/comments/4pvsy0/armiger_what_do_you _think/