MARTIAN MANHUNTER Shut the hell up.

How about a common ancestor from elsewhere, descendants of whom settled on both Krypton and Daxam after which they both developed in different directions with a slightly different appearance/physiology , and at some point diffenrent political systems, the same way humans all came from from Africa or some 'Eden' or 'outer space', depending on your personal convictions and educational background which you prefer to refer to, and colonized the world from there, adapted to different environments, developed different ideas and principles and eventually came into conflict because of those differences. And that is of course one of the underlying themes of this episode, and well, the whole show.

True. It's amazing how many sci-fi shows use the same tropes.

So like Romulans and Vulcans.
Yeah I used to love dying, but that speech really turned me around.

You need to research the definition of humanoid. It can mean "human-like in appearance" as you're trying so hard to argue, whether you believe it does or not.
He who makes a beast of himself gets rid of the pain of being a man.

Humanoid refers to shape, ie two arms, two legs, and a head, attached to a torso.
Human-
like
refers to appearance, ie they can pass for human. Kryptonians (and Daxamites) are human-like. Green Martians are humanoids who can shapeshift into human-like appearance.
Tommy how's the peeping?

I don't know what your point of that was but the very definition of 'humanoid' is having the appearance (or shape) or a human. Kryptonians very much fit that bill, and are thus 'humanoid'. You can try saying otherwise all you want, but the above poster was correct.
He who makes a beast of himself gets rid of the pain of being a man.

You mean human-
like
, not humanoid.
Tommy how's the peeping?

Not as "impossible" as Kryptonians being so humanoid.

Actually they disagree as to which is the descendant and which is the mother planet.
Daxamites feel it is Krypton that was the settled location.

People on earth have no problem starting wars with each other. How long do you think it would be before we started a war if we colonized moon. It would take 2 generations and then the moon people wouldn't consider them earth people, and some anti-mooners would start making trouble on earth, and before we knew it. War.

Ohhhhhhh Supergirl thread, don't you dare be sour. Clap for your Daxamites and Kryptonians and feel the Power! It's a new day , yes it is!

The universe is infinite, and in infinity everything is possible.

Suspension of disbelief will break in strange places for everyone.
I don't know how the story will unfold, but its perfectly plausible for Daxam and Krypton to have a common ancestor in the series.

May be share a common ancestor with Kryptonioan
Two human looking species evolve on the same solar system with similar level of technologies

I was not stating anything against your statement, or I would have replied to you man.

Assuming that was directed at me, where did you get the idea I was arguing against Martian Manhunter. He's a great character. But if the OP had a problem with kryptonians and Daxamites being from the same system, then the same applies to Humans and Martians.
In the kingdom of the blind, you're the village idiot.

You are arguing against Martian Manhunter. What is wrong with you?

Mars in the habitable zone, if a number of things had not happened there would be life there today because once upon a time we know Mars was Earth like before Earth was Earth like.

If Daxamites are the descendants of Krypton, then its more like one species evolving on a single planet. But if that's a problem, how do you feel about Mars and Earth doing the same thing?
In the kingdom of the blind, you're the village idiot.