Craig Orbweaver definitely has thumb buttons. One on "thumb rest" and one above.
I wasn't sure at first, but I found it listed somewhere.
It would have been a deal breaker for me too -my whole number keymap relies on holding upper button, and lower is always enter- so I made sure of it.
Tartarus is just a slightly cheaper Nostromo without the wheel and with one more key in it's place.
Personally I don't use the wheel so if I wanted a direct replacement for the Nostromo I'd take the extra button & pocket the savings with a smile on my face.
But I'm hungry for the extra row of keys on the Orbweaver.
If you're stuck on the wheel then the Nostromo would be the best bet. It looks like they're continuing all 3, which is good.