Array formula to avoid cell value repitition

Hi,

I am calculating Variability based on daily Production of analystmedian daily variability report.xlsx .
The Variability formula = (Median of Production count of agents falling within top 25% / Median of Production count of agents falling within bottom 75%) / Average of production.

Assumptions / Exceptions
1. If Rounddown count of top 25% = 0 then Top 25% Count = 1
2. The productivity is calculated and listed in the same worksheet daily. Thus the productivity cannot be sorted in descending order for a day.

The formula in attached worksheet works fine except whenever there is repetition of Productivity count.
I am open to VB / Array formula.
Please assist.

Thanks,
HP

Please delete this post! The other post has updated file.
I was trying to delete it myself but could not find the option to do so.
Thanks for quick response.