The easiest way to do this, if you're strictly using accounts, is use only one account - FTEs - as a Flow Account Type. You're able to report every view required. You can load/enter either Periodic or YTD values - being careful about your scenario's No Data settings.
The issue that you need to solve for is the Opening Balance. A different number needs to show on a report depending on the View (Periodic/Qtrly/YTD). This is best handled by creating a Dynamic Calc account that shows the correct number depending on the View the user wants to see.
