No, this is not right. The PEO is paying you "on behalf of" a specific employer (even if your check is coming out of the PEO's account). So you should get 2 W2s with separate amounts from each employer.
TriNet (a large PEO) stores employees as SSN so if you have ever worked for a company that used TriNet as their PEO, you are in their system. As an employee, you should see a dropdown at the top and you can only see ONE employer at a time and you have to use the dropdown to switch around.
The only reason you can get ONE W-2 is if you work at a temp agency. The employer technically pays the temp agency and the temp agency pays you. So even if you got billed out to 10 different "employers", you are still an employee of the temp agency and you get ONE W-2 but technically, this is NOT a PEO situation