Count uniques with several conditions

Hello,

My situation:
I have a list of companies that receives investment from different investors in different time periods. The timeperiod are classified into different "Rounds" and the investors are classified into A and B type of investors. I want to calculate number of unique investors that invest in Company X in Round Y given the investor classification. I have achieved this (with a lot of help from the forum) in columns J-K.

My Problem:
I have undisclosed investors in the data-set, which are treated as one investor, e.g. if we have one undisclosed investors in round 1 and 3 in round 2 - only the one in round 1 will be treated as a unique investor - I want to change this. I want to create the following rules for the Undisclosed investors:
1. If equal number of Undisclosed Investor of type X are found in round Y+1 as in Y, it shall be assumed that these undisclosed investors are the same and hence no new Investors shall be counted.
2. Example: If we have 2 Undisclosed investors of Investor type A in round 1 for company X, and 3 in round 2. The difference (3-2) shall be counted as a new investor.

Columns L, N-O is where I wish to fill in my data. I have given a manual example of column L with comments of the rationale in column M.

Big thank you in advance for the help - I have struggled to find a solution.