It just occurred to me a much simpler yet very functional solution! The Canvas Pages can be collaborative spaces. You create a group assignment with URL submission as delivery method and individual grading. Each group of students will have their own space to work in the Canvas Groups. In there they could work in a Canvas Page building the assignment response.
They will deliver their Canvas Page URL to the assignment. The teacher will be able to open the Page inside SpeedGrader (it will open the entire Canvas inside the SpeedGrader) and through the function View Page History the teacher will be able to navigate in all different revisions saved by each student during the construction of the assignment (timestamps are shown).
It doesn't mark the content that was edited by each student like the Google/O365 option. It will show the entire page modification saved by the student. By elimination would be possible to see how the document evolved and the students that contributed more!

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