Sum Simultaneous Operating Hours

I'm putting together a workbook which tracks operating hours for 17 pieces of equipment (units) at 7 job sites.

I need to track and record the number of hours where at least two of units 1-6 operate simultaneously each month.

So far I have only succeeded in creating another table which pulls all records for units 1-6 from the Log. The table can then be sorted by date (for some reason, this sorting only kind of works) so simultaneous operating hours can more easily identified and summed manually.

I'll attach a workbook with mock data which shows what I have so far. The complete workbook also does some other calculations which I have removed for clarity. That is why there is some "extra" info in the workbook.

The workbook is set-up where:
LOG: This is where the user records when each unit was operated.
LOG2: This is where I've attempted to isolate records for units 1-6 and sum simultaneous operating hours.
Factors+Limits: This is where the fields for the lists are stored as well as other factors used throughout the workbook.
Monthly: I'd like to be able to records simultaneous operating hours here.