Change in work location within the MSA of Primary work location while PERM in process

[BSP]

I'm currently working for client A at Washington DC and looking to pursue a new opportunity with client B in McLean,VA location. My current employer had filed my PERM on 10/29/2014 mentioning Primary Work Location as Current client (Client A) address at Washington DC and the PERM is in process. The PWD and the Ads were done for Washington DC. My employer is based in South Carolina and do not have an office in Washington DC. An attorney mentioned that since both Washington DC (Current work location of Client A) and McLean,VA (New work location of client B) are in same Metropolitan Statistical Area(MSA) and we do not need to refile the PERM,but we can apply I140 with the latest (client B) address and mention that both Client A & B are in same MSA.Please advise if this is the correct process.