Struggling with a spill function

I'm working on a report template. Auditors find low, medium, and high priority issues. Each priority has a certain point value. The point values are stored in a lookup table on a sheet named "Lookup".

The sheet where the function I want to spill is used has a number of rows. There are columns for low, medium, and high. For each row, I want to count the number of a priority, multiply it by the points for that priority from the lookup table, then add the low, medium, and high points for that row.

This works, but it doesn't spill:

=SUM(B2*'Lookup'!$E$2,C2*'Lookup'!$E$3,D2*'Lookup'!$E$4)

B is the low priority column, C is the medium priority column, and D is the high priority column.

I replaced cell references like "B2" with spill references like DROP(B.:.B,1). I'm using drop to exclude the initial header row. My problem is, this didn't spill, it just performed the calculation on all the rows and displayed the total in the cell with the formula. What I wanted was for the formula to spill down and only display the total for that row, all the way down.