i mean it seems to me that aliens are likely to either be completely different from us or remarkably similar, depending on their environment.

Like look at how things on earth look: stuff in the ocean is either a fish or something completely unique and fucked up, and on land we have a series of ecological niches that reappear across time and location to the point that it’s kinda hard to tell the different incarnations apart.

I don’t think it’s that unreasonable to expect the odd humanoid alien, we should just also expect a bunch of them to be crabs and slime molds and fish.