How to design a fast formula to loop through assignment records by date and effective sequence.

Summary: We have a seniority date formula that loops through assignment records, looking at action codes and adjusting the seniority date based on rules for those actions. I does loop through the records by date, but an issue came up recently, and I noticed if there are multiple records on the same date, the formula does not read each record by effective sequence. This is causing issues with our seniority date calculations.

Content (please ensure you mask any confidential information): We use this code for the loop: while PER_HIST_ASG_ASSIGNMENT_ID.EXISTS(k) LOOP

Is there a way to also make this look by not only date, but effective sequence in order?