The most common and most likely answer to this crossword clue is the 9 letter word INFERIORS
I've seen this crossword clue in Financial Times
I
N
F
E
R
I
O
R
S
More clues leading to the result INFERIORS
Buddy explains!
The straight part
We know that "Those 3" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case those 3 = inferiors.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does INFERIORS mean?
INFERIORS noun- A person of lower stature to another