ACS Payment Evidence, Missing Salary Slips & Company willing to validate transactions

When I joined my former company in 2020 (I have left it recently), it was still a startup and processes were not in-place. I have the evidence of monthly salary being deposited in my account but company could only provide salary slips of last 5 months. Company is willing to have a document created mentioning all the salaries and sign it on their letter head (along with my bank details etc).
I would like to know if this is fine and if ACS will accept it?

Thank you

I think they will be able to accept it if supported by bank statements.