Before I begin, automatic integration is covered in AR 600-8-19 paragraph 3-17. With regard to varying standards, I would ask you to look over AR 623-3 and review the first chapter. It specifically states that the Army changes policy and procedures to meet the changing needs in war and in peace.
See AR 623-3 paragraph 1-8
(3) The ERS combines major elements of counseling, assessment, documentation, and integration with other personnel functions to meet the needs of the Army, rating officials, and rated Soldiers in their current environments. Its basic foundation—to evaluate today’s Soldiers to select and develop tomorrow’s leaders—will remain consistent.
(a) Rating officials assess a Soldier’s performance and potential against standards—the Army Values, the Army’s leadership doctrine framework, the organization’s mission, and a particular set of duties, responsibilities, tasks, and objectives using a series of box checks, narratives, bullet comments, and evaluation report rating techniques. The intent of the ERS should be to drive rated Soldiers to meet or exceed the standards. While standards or techniques may change, the ERS will continue to be the most accurate and effective assessment tool and development system possible. It will accomplish its mission of developing people and leaders.
I reference this to explain that the Army’s needs change, as does its mission. Therefore they will implement methods to achieve the goals for the overall Army – whether we as individuals agree with them or not.