ill add what i know. but first my back ground. i am a union electrician for over 10 years and how i was the measures amps and watts is for a unit duration of 1 hour. so these measurements the rc industry uses always confused me. because if we used this batteries, esc and motors at amp levels I've been taught are batteries spontaneously combust, ESCs would let out all the magic smoke, Motors would be nothing but liquid metal. which leads me to my next train of thought there measurements must not be based on a full hour duty cycle. if this is the case then there 50a, 60a rated number. could be over inflated to what ever the manufacturer desired. because what one company rated as 2 a sec constant would be dwarfed by another company reading theirs as 1/10 of a second constant.

how i select my setup. i get my motors true unloaded current, i take that to 10% of my esc rated current and then select the capacity battery at half unload motor current.
example:
my motor pulls 2 pole brush-less motor pulls 5 amps @ no load. i will select an esc no less then 50a as minimum and i may go to 60a 2%for extra over head.

5(amp motor)=10% * 50a (esc), 5(amp motor)=12% * 60a (esc)


i then select a battery atleast 50% of my motors no load draw as a minimum capacity battery.( i don't give c rating much pull,i give it to capacity)

5(amp motor) *50%= 2.5 (amp battery minimal)

i have given this much though on 4 pole motor esc selection and i always when with the largest battery i could find.
i haven't given it any though on 3S or more cell batteries so i don't know how it may if at all scale.

not sure is then in for worth 2 cent or the time it took to type