ACS Reassessment documents - proof of co-worker employment

Hi Sir
Please clarify on two Queries in ref to file for ACS .

  1. I have taken a Statuary Declaration from a colleague. So do I also have to submit his employment Proof as these are confidential things and my Colleague may not give. I have however taken a letter from company that i do work for the tenure.So please clarify if Employment proof of my colleague is mandatory ?

  2. My company was been Acquired by successively three times ,so my Salary slips and Form16 Employer details shows different . So suggest how to overcome this . Its the same company but renamed after acquisitions.