https://www.rugbyleagueproject.org/seasons/nswrl-1990/round-5/canterbury-bankstown-bulldogs-vs-cronulla-sutherland-sharks/summary.html
You have listed that the scrums were won by Cronulla 6-4. They were won by Canterbury 6-4.
An hours highlights of the game is here:
https://www.youtube.com/watch?v=9hlLjui0QSU
at 43:30 they give the scrums & penalties at the time & Canterbury were leading 5-2, so Canterbury have already exceeded the 4 you have listed. AFLTables has it as Canterbury 6-4. as well.
https://afltables.com/rl/scorers/games/1990/199004150607.html
It's also what is in Middo's annual.