Using LIPO battery to power Adafruit servo driver + MEGA2560

Hi everyone.
A few days ago I tried to figure out how to power an ARDUINO MEGA 2560 + various components using a LI-PO battery

Ok, now I would like to feed, with the same battery, ALSO the Adafruit Servo Driver 16ch (which feeds 12 servos):

Obviously I have to add a new STEP-DOWN (more 'forced' than used to power the MEGA and the various components)

Ok here is the scheme:

Please can you check if it's all ok? I really scared about my next steps!
PS: really sorry for my weird english!