In the Fender article, the first string must be G because later on, it says "For five-string basses, cut the fifth string[...]". Five string basses have a G string like fours, they add a B string. Since fours always have Gs and assuming they order the strings in either ascending or descending fashion (diameter), it would follow that the fifth string (B) must be next in order to the second-biggest diameter, thus E, which is #4.
So:
1 G
2 D
3 A
4 E
(5 B)
What you'll notice is that it looks like the beginning of a TAB transcription.
However, there's no standard to this. Around here most call the E string the first, but whenever possible I would call the string by its pitch and not some undefined number. As you see, it already gets messy if you go beyond 4. Around here, you'll also find 6 or 7 string basses, that'd be pretty hard to fit into.