Dynamic Name ranges and data validation problems

I think you are making the same mistake that I see time and time again. You are mixing up the two elements of data capture and final reporting. The two require quite different treatments.

A lot of people start by designing the form that they expect to see as the final report, and then wonder why it's so difficult to subsequently analyse and summarise or extract information from it, Yours exhibits all those features.

You should always capture data in a simple two dimensional table and worry about reporting information from it afterwards. Without exception doing this you will always be able to easily obtain management information. Rarely is this the case if you start the other way round.
You will also throw open the whole wonderful world of the powerful Pivot table functionality.

Can I suggest that you change your Data sheet - which I assume to be the Commission Paid tab.
Keep the same A:G columns but insert a new column A for the Date. Now record everything in one long table and use a Pivot Table for analysing the data. I'm not sure what your current Column G is meant to do - or be used for, but you could adapt it if it's meant to start afresh each month.