Start sequence on a variable column without "array not expanded" error?

In one sheet, I have columns for each month. In another sheet, I define start countdown in: with a cell 04/2023 and # of months as 4.

The desired result is starting under April 2023, I want to see a countdown of 4, 3, 2, 1.

I can use the formula =sequence(1, Rules!$B$26 + 1, Rules!$B$26, -1) but only if I manually add it under April 2023.

I tried doing =if(text(B1,"MMyyyy")=text(Rules!$B$25,"MMyyyy"),sequence(1, Rules!$B$26 + 1, Factors!$B$26, -1),) for all the cells in the row, but it gives the error "Array result was not expanded because it would overwrite data"