If that is the actual missile, they seem too small to have that capability.
That was my impression as well. But that is what the article says.
And you might remember that one of the things that the Chinese supposedly got from the Clintons was the plans for the W88 war head.
If they improved on the W88 and further miniaturized the war head you might get 10 war heads in the nose of that missile.
After all they have had 20 years to improve on the design.