As for being the "orcs of the sea," that made me think about how only the stronger humanoids seem to have aquatic variants, for some reason. I mean, we have scrags (aquatic trolls), merrow (aquatic ogres), and koalinths (aquatic hobgoblins); where are the aquatic orcs, goblins, and bugbears? I suppose sahuagin fill the same adventuring niche (having 2+2 Hit Dice, which is 11 hit points on average), but in terms of "feel," these guys don't come across as the same...though I suppose that's due in part to how The Sea Devils portrays them.