There is no piece limitation where weight allowance applies
That screen shot just states that the max weight per bag is 32Kg
if you were on a route where piece allowance applied and were in economy class , you would be allowed 1 piece max 23kg without charge; if bag weighed between 23-32Kg , then an excess would apply
There is no problem taking 1 x 30Kg bag - or 2 x 15Kg or 3 x 10kg bags etc since you are on a weight based itinerary