In addition to your query, you need to adjust your program internal table or mapping fields of internal table (Depending upon the FM you are using) according to the excel instead of your Program.
The templates should be created in some Specific order as mention below :-
1. It should be in accordance to screen flow sequence and should also have the same Field sequence so that it will be easy for the user to check the same in customer master.
2. Template should be mentioned and also specified (In excel also) with the Mandatory fields in the customer master, so that while filling the template the user should not leave this field blank. e.g.Like for partner function "Sold to party" Account assignment should be made mandatory.
3. Better note that the customer master data screens and mandatory fields can be changed with partner function e.g "Sold to party" or "Ship to Party". Either make a separate program with respect to partner function otherwise you need to handle the screen flows pragmatically.
I hope this is enough to resolve your issue.
Regards,
Rahul