It is interesting.
I've had a go at running the numbers on that middle 8 sections of the league.
I did it where a team (Bradford). Won the opening 4 games. They hit 8 points.
Then they rest thinking they are safe with 8 points. Turns out that in my senario Cas finish above them on 12, Wakey on 10. And 2 other teams Featherstone and Fax get 8. Meaning you can't hit 4 wins and relax. You have to play into the 5th week and try to win that week.
It would take someone with a proper simulator to run all the possibilities. But if I change one result a Cas win over Featherstone, into a Featherstone win over Cas. Suddenly Cas are equal top on 10 points with Wakey and Featherstone. Bradford and Fax are in a playoff.
I can make it so Fax finish in 4th and Bradford 5th after relaxing in week 4. But basically you need 5 wins to be certain of safety. Any thing less and then other teams results matter.
I'm not going to do it again though as it takes an age, but anyone can do with with an excel spreadsheet.