Student Visa Bank Statement

I'm applying for a Polish Student Visa (Type D) for a Master's program. My father is my sole sponsor and is officially retired with a relatively low monthly state pension.

Main Funds (9,000 EUR): Deposited into a Euro account, fully documented with an official liquidation receipt from a long-term Private Pension System (BES).
Daily Account: His pension account shows low/regular income and recent slowing activity.
Extras: Property deed, car registration, notarized sponsorship affidavit, and a cover letter.

Does having a low monthly pension income on the sponsor's primary account increase rejection risk, even though the main 9,000 EUR proof of funds has a clear, documented origin?