Combining a COUNTIF, a SUMIF and some operations into a single dynamic formula

Hello,

I'm supposed to be the Excel wizard at work, so when someone asked me for help I swaggered over with my usual confidence, only to be totally stumped. Please could someone help me simplify an overly-complicated sequence of calculations into something more tidy and dynamic?

I created the attached spreadsheet to explain what the current solution is in a simplified manner. I annotated it to explain what I would like to do. Basically, its a spreadsheet that allows workers to write down which projects they've been working on, and the output is a breakdown of resources that have been added to each project.

If it's too much to ask for a finished solution, would anyone be willing to point me into the right direction? I had a feeling that maybe array formulas could help me, but I've now learned all about them and still can't quite come up with a nice simple solution.

Many thanks for any help you can offer!

I can't seem to work out how to upload a worksheet, so just going to share it via a OneDrive link:

https://1drv.ms/x/s!AkK3zAtp-nuMit9Pa9QG2Z7nFAA5zQ?e=FQcxx3

Best,

Eddie