Update record in second table when value changes in first

[PokePoke]

I have two tables, Projects and Employees. Employees are assigned to a Project as a linked record. I'm trying to create an automation that on record updates and creation of the employee field on the Project, a note field is updated with something like "Employee A assigned to Project B on X/X/XX" to keep a history of the assignments. 

How do I find the note field of the Employee to update when the change happened on the Projects table? The Find Records action won't let me select the Employee Name or RecordID. 

[Sho]

In my image, it would be difficult to complete the history function with just the notes field.
How about creating a history table that records projects and employees?
With that, just let Rollup complete the list.