Unfortunately, in situations like this, there is no possible way to 100% confirm that this will fix the issue, unless someone has seen the issue personally before, and even in that situation, that person may have had a different issue causing the same symptom.
As a technician, my order of operations would be as follows for this issue,
1) Cashe Wipe/Factory reset
2) New front camera
3) New back cameras module
4) reflow on Camera Data Line
5) Motherboard
the most effective way to go through this procedure, would likely be to pay a technician to do this, however, if you insist on trying yourself, I would purchase from a retailer that allows returns. If you do this, you can buy all of the components, then return the ones you don't need. this will save you time in the entirety of the process.