Struggling to Merge Two Different-Sized Tables into a Third Table

What I'm trying to achieve is combining two different-sized tables into a third that groups together duplicates. I've provided the methods that I've attempted thus far and their results in the sheet linked below.

Sample sheet: https://docs.google.com/spreadsheets/d/1vbYTL1hnh_-HNY0RL9w5yAR920zPxouG4jwsNX-MyC4/edit?usp=sharing

https://preview.redd.it/qrq4xpiyv6ge1.png?width=2331&format=png&auto=webp&s=aad0aee90f68dac2e6770d3feed5a34f06d2889d