As with the article on goblins, this one gives us a brief overview on three monsters: the kobold, lizardfolk, and troglodytes. Likewise the overviews we get match up with what I expect; kobolds are reptilian, set traps, and have an affinity for dragons, lizardfolk live in swamps, use blowguns, clubs, and turtle-shell shields, and troglodytes live underground and smell bad.
|It even has the scaly skin.|
I like that lizardfolk are not inherently evil, especially considering that there are plenty of evil humanoids out there. While I remember Semuanya--as he/she/it was featured several times in 3rd Edition--I had to look up Sess'Innek, which I guess was a tanar'ri lord originally from 2nd Edition's Monster Mythology (getting an update in 3rd Edition's Fiendish Codex I: Hordes of the Abyss).
The article also mentions half-demonic lizard kings, which could make for a solid adventure hook when raiders start abducting humanoids for sacrifices and/or giant fiendish snakes start slithering about. No mention of khaasta or hermaphrodites (which I recall being a big deal).
As for troglodytes, well...I vaguely recall maybe running into one in a published adventure, but mostly I remember them throwing stuff at me in the D&D arcade game.
As for the aquatic fare, though I have only really used sahuagin in Eberron campaigns I am not opposed to locathah and merfolk appearing in the initial run (in fact, I have plans for merfolk and the Court of Coral in an upcoming campaign). I guess this is largely because they never got a lot of, ahem, depth. In 3rd Edition I recall a monster entry and...that is it. In Eberron sahuagin were a bigger part, often serving as guides for ships heading to Xen'drik.
In other words, none of the poll choices work for me. I do not think that they all belong in a supplement, though if they are best served there then go for it. If they can be delivered with some compelling flavor and adventure hooks (or even an adventure) in the initial run, all the better. Just do not give us a merfolk stat block and call it good.