So with SD40-2s I am having problems with traction what should I do to reduce the wheel slip and is it my fault I can't get the consist moving
Make sure that you're also setting up the trailing loco properly to help pull. I rarely have to use sand on Sand Patch Grade. Only when doing hill starts with heavy trains in wet conditions.
https://forums.dovetailgames.com/threads/ac4400cw-distributed-power.26976/#post-174267 The correct DPU and Banking setup solve all traction problems. Very rarely I use throttle over notch 4 or 5.