Best Approach Question - Merge Tables or Connect Together?

Table 1 is essentially the list of employees who were still at the company at the end of 2018.

Table 2 is the hires this year and Table 3 is the exits so far.

Below is a quick example I just created to get an idea of what it would like look with data slicers if possible.

Yes, I just want to show the rise and fall, with the ability to use data slicers using my org levels and also dates if possible.

Thank you for responding to my request!