Will just leave these builds here. Hopefully they can be helpful.
I'm running +spd/-hp Jeorge. I'd love to try a +atk/-hp one, but have never been able to pull that specific IV. Don't mind so much tbh, since this guy has been with me for such a long time (March 2017) and I'm used to how he works. I prefer the -hp bane, because summoner support will cancels it, but I think could be - res great too.
Image 1 & 2 - Parthia :
Parthia makes him a incredibly flexible unit. Depending on what you want/need on your team, you can have him as a generalist offensive unit, or a dedicated ranged counter. Either way thanks to Parthia he'll always be able to fill the spot as a pseudo dual phased unit vs ranged. I hope the two builds I have can demonstrate that.
The first image is a more general. He usually more than capable of taking a hit with full hp. This will activate Brazen atk/spd, Desperation and have Draconic Aura ready on your player phase. The second one is more of a dedicated ranged counter. Dull Ranged is used to neutralise blade tomes. The B-skill can be replace with Vantage, and the Deflect Magic Seal can be be used if you want a Rein counter. With Brazen + Vantage he can solo Book 2: Chapter 9-3 on Infernal via positioning on a Defense Tile, and also Book 1: 11-5 Infernal with a Hone Atk. Overall I think Vantage would be more useful for a Jeorge with a +atk IV.
I find that he's one of the few ranged units who would prefer Reposition over Draw Back, as it'll always help to keep him in a offensive position. At full hp, or if you're toying with Vantage shenanigans he's usually good for staying in enemy range after pulling an ally out.
Seal wise, on high merges, I prefer atk/def +2 over atk +3, just because I think the tiny bit of def helps. If you're running Def Tactics on your team, he'll be carrying 38 def. I also like running double Smokes, double Drives or Savage Blow 6. It just really depends? He's a very flexible unit to tailor around a team, and your needs.
Lastly, I just want to add that I think LnD or Fury would be better if you're running Jeorge on lower merges. His base are quite balanced at that point. With the Parthia refine he's still going to be difficult to one shot with magic. So I think the trade off for getting a better statline from the get go is worthwhile.
Image 3 -Rival Domian/Grand Conquest Clarisse Bow :
This can probably be run on any archer. With more defensive ones like Gordin, Leon etc.. could use Close Counter for A. I still live to keep the Brazen because again.. even without Partia he's quite difficult to ohko on high merges, so it makes him more murdery... (and dead enemies do 0 damage :P).
The main purpose of this is to support other allies by harassing enemies. Anything he doesn’t kill will have to deal with -5 atk/speed debuff from the bow 14 splash damage from SB6, and Chill Def is there to hit anyone with high Def. If they get caught in Growing Wind too, well… good luck to them ..
Growing Wind is the chosen special for its 3x3 square damage area. Handy for carpet bombing respawns around castles and enemy clusters.
Image 4 - Firesweep
Very general Firesweep build. I used to have this when he was on much lower merges (under 5). For Jeorge I prefer it to Brave Bow, just because of the extra mt from Firesweep, wich goes well with my +spd IV. If he was +atk I might have ran Brave Bow. Generally I think Parthia is too good to pass up esp. on higher mergers as he get really close to having mixed bulk.
I think it's also possible to do Ardent Sacrifice + Brazen. As the -10 hp is enough to drop him into Brazen range. I still prefer LnD because he gets the offensive statline from the get go. For B-skills Chill Def/Chill Spd is also pretty great.