If you want the variables named using the ID variable to appear in any specific order you might be able to do that by using
PROC SORT
DATA=WORK.QUERY_FOR_APPEND_TABLE_0000(KEEP="SUM_of_Count(Distinct(AKA_CIN))"n SVC_FROM_DT_MM Age_Group)
OUT=WORK.SORTTempTableSorted
;
BY DESCENDING Age_Group Svc_from_dt_mm;
RUN;
Maybe. If the ID variable does not have all the same levels for every BY value they will not be created in the order that that they appear in each BY variable group. Since you didn't provide any sort order for the ID variable they are haphazard within the values of the Age_group.
BUT the question is "why bother?" Any output that you create for people to read can specify the order of values and SAS doesn't care about the order of the variables in the data set.
I have to say you are willing to deal with way uglier variable names then I would touch.