Obvious difference is national language rules for displaying dates.
Second is how a particular format will display a given value with a short length.
data _null_;
d = today();
put d= worddate10.;
put d= worddate15.;
put d= worddate20.;
put d= nldate10.;
put d= nldate15.;
run;
On my system today the log shows:
d=March
d=Mar 23, 2024
d=March 23, 2024
d=03/23/2024
d=March 23, 2024
In my default US national language support note that the Worddate examples (the first 3) pretty much start the same just adding text in different places as more character positions are specified.
NLDATE chose a very different display for the short version.
No idea what any specific other language might prefer.