Manipulate data for Row Span logic in ag grid

I have an ag grid with row spanning and I am able to do row span for first and second column. Can anyone please help me for row span logic for rest of the columns (notes, votes)?

I think row span should be calculate/manipulate dynamically it can be multiple columns in future, so right now my logic is wrong i think.

Here is the stackblitz.

Can anyone please help me here for the same

Thanks