Their similarity speaks to their purpose though. Nearly all the nations or territories/provinces using the ensign design (red ensign, blue ensign, white ensign, etc.) are historically British colonies or members of the British military.
Just as the New Polar Order's flag is very similar to that of the New Pacific Order. The design similarity of the flag speaks to it's roots and those who had a major hand in founding it.
The base shape design of the NPO and NpO flags are the same, thats it, the colours are different, the centre is different and they are more than distinguishable at a distance.
All of the British ensign flags look pretty much exactly the same.