Matt Yglesias says:
There's no denying that this is a pretty amusing poster. Still, it reminds me that I think the film engaged in a bit of revisionism when it portrayed the Autobots as humanoid-shaped robots capable of change into cars and trucks and so forth. My understanding from my childhood is that we should think of them as car-shaped robots capable of changing into humanoid-shaped ones. After all, they're called autobots, like automobiles. Their essential property is their car-ishness.
No surprise that Matt is being ahistorical, and relying on analysis of terminology, instead of relying on the facts (his background is in philosophy). As it happens, in the cartoon the Transformers are shown as humanoids on Cybertron, with their transformed state being different! In other words, the constant and essential aspect of Transformers was their humanoid, not their mechanical, form. Additionally naive human psychology does not generally attribute theory of mind to machines, but obviously Transformers were active agents.
Matt's argument makes sense with Voltron. This was a mechanical entity whose humanoid form was entirely incidental and cosmetic, and the constituent lions were themselves mechanical objects under human control.
Voltron would wipe the floor with any and all Transformers, thus the answer must always be Voltron.
So what would you say about the Sharktacons, whose amphibious form seemed to be more "natural" than their humanoid form (in the 1986 movie)?
Or the Dinobots, who's Dinosaur form also seemed more "natural" than their humanoid form (in the original TV series)?
(Note that neither the Sharktacons or the Dinobots had Cybertron origin.)
The bottom line is that their form as natural kinds are primary, rather than their form as artifacts. That's because even robot cartoon obsessed little boys care more about living things than doo-hickies.
Yglesias is autistic, so he assumes that everyone else would see the gadgety aspect as primary. In reality, boys anthropomorphize machines, making them walk, talk, fight, etc.
In related transformers news, the new(ish) cartoon Transformers Animated is actually pretty good ... and the main human character is a South Asian little girl. Clearly we are all under threat from the sub-continent when even our children's cartoons are no longer safe from their cultural hegemony!
The Transformers catchphrase is "Transformers: more than meets the eye". People would react to humanoid robots walking down the street, but they don't give a second glance to cars and whatnot, even if no one is actually driving them.
The object-forms are clearly secondary. They're disguises that hide the truth. The humanoid forms are the one thing that all the robots, good guys or bad, share. Their disguised forms are all different (with an admitted emphasis on transportation devices).
Why would anyone think the object-forms were the important ones?
My principal early exposure to Transformers as a child was the spinoff Beast Wars cartoon. In that show, the transformers were more or less purely robotic, with their disguise forms serving a shielding purpose to protect their robotic forms from damage by the ambient levels of a power-carrying crystal on the planet surface. I don't think the transformers even had alternate forms before developing them out of necessity on that world.
And in that case the alternate forms were animal, not automotive. Presumably the actual nature of the transformation is very ad-hoc, and possibly not required at all under normal circumstances.
I would say that naive human psychology is actually predisposed to impose theory of mind on EVERYTHING ...