First, (RWT is the possessive form of (RWH,
which also appears several times as "nakedness".
However, (RWH can also have the broader meaning of "missing something",
where that "something" can be other than clothes.
This is similar to the English use of "bare minimum" or "bare
essentials",
where "bare" takes a broader meaning than "naked".
So, (RWT DBR means that the man found something missing in his wife.
(RWT H)RC means "what the land is missing", i.e. where there is
something
missing in its fortifications.