I think Yelmalio vs Elmal are really mostly a societal/cultural issue.
"Elmal" in Heortling cultures is the allied god, a faithful ally. They will cooperate with "taking a dip" (although not in such powergame-y terms -- they want actual faithfulness, worship, earnest regard from their Initiates).
"Yelmalio" will be much more stand-off-ish, lthe priests much ess likely to accept Orlanthi who come to them saying they want to Initiate...