OpenAI is at least arranged by size of celestial feature. Anthropic did arrange them by size of a written work. But I think Fable and Mythos made it a little weird. As for Google, no idea other than Hydrogen is small.

Having said this, I don't defend this trend at all and also think a model picker ought to be good enough with at most three tiers.

OpenAI - Celestial body size.

Anthropic - Literary scale.

Google - random elements with no clear relation to model value/capacity.

A fable is bigger than an opus? An astra is bigger than a sol, which is also a star?