When people argue about club's and their history, trophies and success cannot be taken in isolation. By Des Parrot's argument Cardiff's 1927 FA Cup win won't count soon as it will be over 100 years ago!
Sunderland have been League Champions 5 times and won the FA Cup twice. So 7 major trophies. They have won the league title more than Spurs (who have only won it twice) and more than their local rivals Newcastle. Both of them claim to be huge clubs.