Migration of directory structure causing a lot of merge conflicts in git

Question

I'm currently searching for best practices or experiences regarding the change of the directory structure in a git repository.

The problem: I need to move a lot of files while the rest of my team is working on those. When those branch are merged (probably beginning with the directory structure change), a lot of conflicts are reported.

Example: All code originates from main.

• A colleague create a first branch work_a from main.
• I create a second branch structure_change from main. I change the structure from this:

a/
  b/ 
    b1/
      file1.go
      file2.go
    b2/
      file3.go
  c/ 
    c1/
      file4.go
    c2/
      file5.go
      file6.go

to this (moving content of c to b):

a/
  b/
    b1/
      file1.go
      file2.go
    b2/
      file3.go
    c1/
      file4.go
    c2/
      file5.go
      file6.go

• Another colleague create a third branch work_b from main.
• I merge my branch structure_change to main. No Issues, history is kept.
• work_a is merged in main -> Merge Conflict on the directories and subdirectories of c/.
• work_b is merged in main -> Merge Conflict on the directories and subdirectories of c/.

I need to change the structure, but I would prefer to have as little impact as possible.

Any ideas or suggestions ? Maybe experiences doing the same operation ?