They are different things. If you turn down the torque/punch/whatever it's called on any particular ESC, you are making the throttle "softer" as it gets to 100% throttle. If you reduced the radio EPA, you are literally limiting it to a throttle amount of less than 100% throttle when you are at full throttle. I personally dial in the ESC with everything at 100 or 0 where applicable on the tx, then use the tx for fine-tuning.