Filter and Group by using Power Query or Excel formula?

Let’s say I want to calculate average annualized salary over my company.

My data set is

Department | Employee Number | Salary Grade | Annualized Salary | FTE %

Someone can work 60% on a level 1 salary for department A and 40% on a level 2 salary for department B. In the dataset this person has 2 rows.

There are two metrics I want to calculate:

1. average annualized salary across the whole company
2. average annualized salary across the whole company excluding department B

For 1 - that employee’s annualized salary need to be recalculated as 60% * lvl1 + 40% lvl 2 to get one row per employee

For 2 - I filter out all department B salaries so that employee’s annualized salary is simply their lvl 1 salary

Question: Should I:

Create two tables in power query, filter out department B in one table using Power Query, group by employee number for both tables in power query, output both queries as tables in excel, create 2 pivot tables to calculate averages

OR

1. Use excel formulas to do everything: filter and group by and calculate 2 averages