When you book the ticket on AF website, it would usually clearly indicate your checked luggage allowance, including any FFP benefits, for example during booking while logged in to my FB account (note hand luggage is also clearly mentioned...).
The same should also reflect if you use the AF app for example, or on the AF website if you check your booking.
Your e-ticket will show your baggage allowance *Excluding* any FFP benefits, so this could give you an indication if you booked a 'light' fare or not.
Even AZ "light fare" T&Cs clearly indicate you should get free luggage as STE -
https://www.alitalia.com/en_it/offer...onditions.html
Members of the Freccia Alata Plus, Freccia Alata, Ulisse, Elite and Elite Plus Clubs will be entitled to:
One piece of hold baggage plus any sports equipment
Change their seat and/or choose an Extra Comfort Seat (only available to Freccia Alata Plus and Freccia Alata Members)
Check in at the airport, only in the lounge if permitted (only for Freccia Alata and Freccia Alata Plus) or at the SkyPriority priority desks (only for Ulisse, Freccia Alata Plus, Freccia Alata and Elite Plus)
I don't think a "strategy" is needed other than insisting you should get free luggage and presenting your FFP card if needed.
Also for future reference AF hand luggage rules are completely irrelevant here as your had your flights operated by AZ and DL, AZ have a much stricter hand luggage policy (only 8KG), this is of course clearly indicated on AZ website and can be found by a simple google search 'alitalia hand baggage' or so.