Lacking staff an advantage at times (3,3,5)

I believe the answer is:
now and again
'at times' is the definition.
(I've seen this in another clue)
'lacking staff an advantage' is the wordplay.
'lacking' becomes 'no' (eg lacking money means with no money).
'staff an' becomes 'wanda' (I can't justify this - if you can you should give a lot more credence to this answer).
'advantage' becomes 'gain' (gain is a kind of advantage).
'no'+'wanda'+'gain'='NOW AND AGAIN'
Can you help me to learn more?
(Other definitions for now and again that I've seen before include "Occasionally" , "From time to time" , "Sometimes" .)
