The most common and most likely answer to this crossword clue is the 2 plus 3 plus 5 plus 4 letter word IM ALL RIGHT JACK
I've seen this crossword clue in The Daily Telegraph
I
M
A
L
L
R
I
G
H
T
J
A
C
K
Buddy explains!
The straight part
We know that "never mind the others" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case never mind the others = im all right jack.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.