I'm not sure if what your lawyer is saying is correct.  You might want to speak to another lawyer just to be sure.  I found this information online that I think you'll find helpful.  They say:

The sad news is that it will generally take several years to obtain a green card, so your employer will probably want to use a temporary ('non-immigrant') visa to get you to the US; once you are there you can embark on the longer project of getting your 'Green Card'.  For more information, read this site.  I hope this helps you.  Good luck