Are you sure you had weighted assignment groups last year? If you have non-weighted assignment groups, then if you choose the gradebook total grade to be shown as a percentage, it will be out of 100%. But weighted assignment groups can add up to 100%. I've used that for bonus points that are beyond the 100%.

The closest I can think of a semi-automated way for Canvas to calculate the score as you describe is to have 4 copies of the Final Exam assignment, each in a different assignment group:

• First one alone, in a group worth 15%
• Second together with an Engagement in class assignment, worth 5%
• Third together with the Pamphlet, worth 20%
• Fourth one with the weekly quizzes assignment, worth 30% (this one may be trickier, since there are 15 of those - would probably need to have a single assignment grade for all)

Where the second to fourth groups have a policy to drop the lowest grade, and within these 3 groups, the final and the "other" assignment are worth the same number of points.

(the rule in each group is the same, to drop the lowest)

The non-automated part of this is that you'd need to copy the Final Exam grade to all assignments, and perhaps in grouping the Weekly Quizzes to one single assignment.

It may also be slightly different from what you asked for, as if a student submits the Pamphlet, but gets a lower grade on it than the final, the pamphlet grade is going to be dropped.