Gonna think on it for a day or two, but my reasoning for Dagon is that it just feels more unique to me, especially with the SBII+10 allowing for SB+65 builds on SAM DRK WAR and SB+70 on DRG. And some fairly practical additional uses: Shining One Impulse Drive, Stardiver, strong Meva... Significantly harder to solo/2box Kin too, as opposed to Gin for Ashera if I really wanted to farm bodies (I do not).
Ashera would be pretty cool on RUN hybrid/DD builds, and is totally what I'd pick on my other character (mage/support jobs, including R15 Carn BRD). But Ayanmo +2 body fills a similar enough niche for RUN, even if not quite as good (especially with Mythic AM3 up). On THF MNK NIN DNC, all of which I do play, I feel like Malignance pretty much made Ashera obsolete. If I'm missing something there, input welcome!
Interesting point about Udug mercs that I hadn't considered! I don't play on a server with much of a merc culture though, so that's not really available to me without a transfer. But yeah, it'd be a PUP nuke piece for me anyway (lol) so not much of a priority.
Shamash imo is the best option (i know you said you dont play mages, but...)
Everyone played BLU at some point in life. If they didnt, they should, for cleaving purposes, etc.
I already have Shamash on my mage alt (separate account) where I'd actually care about it. No interest on this character. The only job I have that can equip it is BLU, which I don't really like much. To illustrate my apathy toward BLU, I took a JSE +1 neck from like r10 to r20 solely by chipping away using the heroism items I got as drops in Dyna runs - just so I
wouldn't have to actually play the job in the event lol. I really only use my BLU for AoE on pre-ilevel stuff (Mythic farming is pretty much it), where I'm totally fine with just using Jhakri +2 for nukes and ignoring DT- since we're talking about non-threatening mobs. And TBH, now I generally prefer BST anyway for AoE.
Ow, well...
For rank 3 i guess i can go with the polearm for abyssea red proc purposes, or the ranged for claiming
Polearm is also a baller lockstyle (the REAL endgame), that you actually get to see as opposed to only appearing when readying a throwing pull... I really wish Grudge had been a lockstyle shuriken, or that they'd add one of those.