Coran was a Zoologist
My family is rewatching Voltron right now, and as a result I’ve been overhearing a lot of Coran’s lines again, and it struck me that we think of Coran as the ship’s engineer/officer/tech guy, but really he’s probably only in that role because he’s the only person left alive in the universe with enough working knowledge of the technology to make it work. It probably isn’t his specialty. This hit me mostly because I realized there’s a lot of evidence of him specializing in another scientific field: zoology. The first inkling I had of this was when the team first gets handcuffed together. Coran says “You get to feed each other! Like a pack of Yelmores!”
This isn’t the only obscure Altean (presumably) wildlife reference that Coran’s ever made. In fact I’d hazard a guess that he’s probably made one like this in almost every episode. I’d rather not go through and make a list, but if you listen to him for a while you pick up on it. He has a lot of knowledge about Altean animals just floating around in his head, and it’s important enough to him that he talks about it on a regular basis.
This isn’t like a human on earth mentioning vaguely that “Oh, I heard once that crows remember the faces of people who have been mean to them.” This is someone who hears you describing a piece of technology that can tell if you’ve tried and failed to unlock it or something like that, and then he automatically relates it to the conversation out loud as if it should be well known to everyone there. Just because he loves animal knowledge so much that his brain automatically makes the leap there.
The real clincher for me with this one, though, is the Weblum video. This was an instructional video about an animal, probably put together for pretty young Alteans. And Coran was deemed enough of an expert on this subject to star in the video. We don’t just get some random army guy or rocket scientist to make a video on whales, do we? No we get a zoologist. I don’t see why Altea should be any different.
The two options I see here are that he was an expert on Altean creatures specifically, or on alien creatures in general. I’m not sure if this factored into his position in the army/royal household or not, but it definitely seems to be part of his background.