I used to work with the engineer who designed many of the power supplies for British military aircraft etc............on being asked about calculation of values of ferrite beads and common mode chokes and Y caps etc to fight common mode noise...this engineer said..."its like sprinkling currents into a cake".
At the time this engineer was working for a consultancy who was working on the same project as i was....but their bit was much bigger than mine.
Beware with diff mode L and C...if you use too big values, you may well get well below the line on the plot in places, but the common mode will be worse due to the parasticis of the big L and C