Firewall Sizing Guide/Tool

Good Day,
I am new here but I have been in networking for the past 12 years, most of them as a consultant. One of questions many persons ask is "how to size their firewall." I created a sizing tool and provided some recommendations for choosing the right firewall. Let me know what you guys think about it. Would it add value to persons? Would you have added any other considerations?
NGFW Firewall sizing guide - Awesome Networking