Powering 2 arduinos and 2 steppers from the same battery.

I am making a 2WD robot right now. I have:

  1. Two stepper motors with 1.2A phase current draw (which is way more than I need, so probably 0.7-1A would do for chassis).
  2. Two TB6600 stepper drivers.
  3. Arduino Uno and Arduino Nano
  4. LM2596 Voltage regulator
  5. Battery pack that I assemble from 4 LiFePo4 cells (3.3v 1700mah each with 3C discharge) connected in series 13.2V total
  6. Low current shields - magnetometer, ultrasonic rangemeter, buzzer, bluetooth and small servo
  7. Later I am planning to install RaspberryPi on board to make processing

Now here is a question. If I use the same supply to power in parallel two TB6600 with steppers and LM2596 which will step down 13v to 5v to power everything else. Should I be needing any decoupling filters and stuff like this? Will I have spikes from the steppers or the drivers will take care of it?