LED lighting circuit HELP!!!

I work at a heavy industry as a maintenance spark!
we are having the yard area extended and some new plant equipment/ machinery installed, part of the new yard extentions is a raised metal gurder walkway 300 meters in length, there are 20 lamp post along the walkway each with 2 x 80watt LED lighting modules on every post so the total load for these lights is80 x 40= 3600 watts -13.9amps total current demand,the BOSS says he wants a 2 way switch at either end of the walkway an though i have tried to lead him down the path of photocells he will not have it.
we have been left a 32 amp isolator by a contracting company in the yard which will feed these lights at source but we will be adding a 16 amp breaker downstream.
we have had some cables dropped at work to feed these sed lights, the cable is SWA 16mm2, my first thought was this had to be wrong ,,,lol....
but after calculating the volts drop along the 300 meters it appears to be correct cable size..in the past i have done some carpark lighting circuits but we never used an cables of this size!!
we would never in a million years get these cables into the terminal housing provided by the post manufacturer so we would have to terminate into an adaptable box under the walkway under every post then come out of the post in lets say 2.5mm2 to the terminal housings....
just seems like regs gone mad to me!!!

So my question is does this 16mm2 cable seem seem right to you guys????
any information or advice would be great.....