I'm having a hard time deciding if I should have the turnouts in the red circle be #4s or #6s. I'm only running geeps and slow speed switching threw the crossover tracks and the siding. But eventually when I add on I will be having long frieght and modern sized engines running on the mainline. If the large engines and frieght cars are running through when the turnouts are set straight will they be affected if I use #4s? Thanks