Just so everyone is clear.
You are getting a new radiator that will have a trans cooler integrated with it. This was one of your deciding factors in buying the new radiator
FYI...
What you are doing is shotgunning the solution which is fine. BUT I would recommend you take it one step at a time.
Swap out the radiator.
Drive it enough to determin of the problem is solved.
If not do the next easy / cheap thing, drive it for enough to determin if the issue is solved.
Then rince and repete.
Personally I would hold off on the electric fans as that will introduce a lot of other issues with wiring etc. Our OEM wiring is not designed to handle electric fans.