should i get heavy armor or raise my dex to 14

[Naofumi]

I'm an artillerist artificer with 14 strength and 11 dex I was wondering which one would be ideal. I've calculated that the dex build is a reasonable strategy at around maybe 10-17% power(initiative, stealth, ranged weapons, out of combat armor, trap disarming, crafting, dex saves) plus 2ac for 3 points and the heavily armored is roughly 3ac(24% power i've calculated) for 2 points. Idk if I would actually use a ranged weapon though I might just help someone else with the help action, and crafting seems worthless. Not sure how much out of combat armor would help. Initiative also kind of wacky to me. Considering artillerist has low range on several turrets I don't think it would matter to go first.

 

[Naofumi]

My strategy is to grab 1 int 1 con, heavily armored feat, 2 int, prodigy or skill expert at 16 with arcana to craft see invisibility scrolls and fireballs, and at level 19 idk what to do at that point probably get my stealth or perception boosted resilient(dex) shield master mobile or lucky too