Asked a lawyer

I asked a lawyer. He said I485 form must be accompanied with a few paystubs to show that you have already worked for the position the employer has been applying for through labor certification. But EAD can only be applied for after 485 filing, so do this mean that my wife needs to get H-1b first (after 140, the IMMIGRANT visa application?)

Isn't green card application for a future position after receiving the green card?

Thank you.