Claes Sael's ship Maria had an odd armament

For a 30-gun ship, Claes Sael's ship Maria had a very light weight of broadside. This is the information:

The ship of Capt. Sael named Maria

Length between stem and sternpost:  134-3/4ft
Beam:                                29ft
Hold:                                13ft-9in
Height between decks:                 6ft-3in

36 guns:
 4 iron gotelingen   12 lbs
16 iron gotelingen    3 lbs
 6 iron gotelingen    6 lbs
 4 iron gotelingen    4 lbs