I have taken a copy of your database and made adjustments to it as follows:
Created new tables beginning with tbl.... using Create.. queries using your original tables.
Added unique Id fields (autonumber and PK) to each new table I created.
With tblPerson, I have also divided Person into atomic fields FirstName and LastName
Created Junction tables tblPersonWorkActivity and tblTeamOfPersons to resolve many To Many issues.
In tblPersonWorkActivity, I have added fields WorkDate and HoursWorked because it seems reasonable to me that a Person can Work an Various Activities BUT only One Activity at a time. And since you are concerned with the Quantity (HoursWorked) those Hours relate to a Person and an Activity on a Specific Date.
I have added a couple of Select queries to show who is on which team and How many people are on Each Team.
I have also added unique compound indexes on the 2 junction tables to prevent duplicate records.
I have attached a jpg showing your relationships and the revised relationships that I think are relevant to your issue.
I have attached a zip with the revised database and some screen shots.
I hope this is helpful. Good luck with your project.