Italian city's birds -- number with their usual formation coming in (8)

'coming in' is the definition.
Although both the answer and definition are adjectives, I cannot understand how one could define the other.

'italian city's birds number with their usual formation' is the wordplay.
I cannot quite see how this works, but
'number' could be 'v' (V is an example) and 'v' is found within the answer.
'italian' could be 'genoese' (I've seen this before) and 'genoese' is found in the leftover letters.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).

Can you help me to learn more?