Neither one of you are exactly correct. Currently there is no regulatory guidance that dictates monthly counseling. AR 600-20 used to explicitly require monthly counseling. It has been changed to read the following:
2-3. Perfomance counseling
Commanders will ensure that all members of their command recieve timely performance counseling. Effective performance counseling of officers, noncommissioned officers (NCO), enlisted Soldiers and DA Civilians employees helps to ensure that they are prepared to carry out their duties efficiently and accomplish the mission. AR 623-3 contains counseling requirements for in conjunction with evaluation reporting requirements. Unit commanders will determine the timing and specific methods used to provide guidance and direction through counseling. FM 6.22 provides advice and makes suggestions concerning effective counseling. Providing regular and effective performance counseling to all Soldiers, not just those whose performance fails to meet unit standards, is a command function. All commanders will ensure that their subordinate commanders have implemented and are maintaining an effective performance counseling program.
Therefore, the local commander should have a written policy that directs how and when counseling should be conducted with regard to E-4 and below as well as E-5 and above. It does not necessarily have to be monthly, but there is a requirement to have a counseling program in place. Consult local policy and procedures.
Personally, I believe that regular performance counseling with the DA Form 4856 is a great way to keep your team focused on professional development and overcoming weaknesses. High-quality counseling packets also make preparing evaluations for your subordinates much easier.