Green card and H1b applied by same employer but job titile changed

Hi .

My H1 B sponsor plans to start green card process for me . The job title for H1B petition and LCA was senior designer but the attorney says that for green card we should apply as “designer” to qualify for LCA.

I am confused and cannot understand , as the employer the same and why would the attonery want to apply LCA with a different job title.

Please help understand !!

Thank you.