Think they can do better!
Do not take this personally. I am speaking solely on a business perspective.
The NRL should stop aligning with horse racing, which is largely watched by drunk gamblers, and align with other sports that aren't in direct competition with the NRL, which are played in the NRL's off-season, which kids love getting involved with and watch (hence why I suggested Soccer, Basketball and Cricket)
1 month of horse racing affiliation, which ends in mid-November is pointless.
There's 3 and a half months with no major races on FTA after the Melbourne Cup. All you're advocating for is one extra month of attention on the game, after the season has ended.
Pick a sport, a proper sport, which ends nearer to when the NRL begins, that way you can build interest and anticipation leading into the upcoming season.
I deride racing because i don't regard it as a sport. This cross-promotion idea, as a concept, would provide little to no value to the NRL because kids (along with the majority of the nation) do not attend or watch horse racing.
Just because you do is not indicative of the nations viewing habits.
It makes zero business sense mate.
Cross promoting Rugby League is a very good idea.
Doing it with horse racing though, is not.