And given the different makeup of the sides after 2014's early start, Williams said Ruapehu's 14-8 victory over them in Waverley on April 12 gave little indication of what would happen at Rochfort Park tomorrow.
"No relevance - they were missing personnel, we hadn't been together very long. [In Ohakune] it's a tough battle, and cold, forward orientated."
What will not help is that veteran No8 Ray Stark is out with injury, while last week's double tryscoring lock Ian Honeyfield is likewise unavailable.
Kieran Hussey came back too early from injury in the Round 2 loss to Pirates and missed last week, being gingerly included on the bench tomorrow.
"If we want him at the business end of the competition, I have to bring him back slowly," said Williams.
Therefore, others have been asked to carry the can and if they step up, the entire South Taranaki team will step up.
Veteran Clint Skedgwell will start at No8 while Jack Hodge moves from lock to cover flanker.
Meanwhile, big prop Kamipeli Latu must prepare for a physical day because if the alpine conditions turn the ground to mud, it opens the door for domination by Ruapehu's front-rowers in Karl Parker, Kim McNaught, Roman Tutauha and representative veteran Shaun McDonough off the bench.
"I personally think Kamipeli is a representative player, it's about the players stepping up around him," said Williams.
Ratana have had six days to get over the shock of their final quarter collapse against Marist and prepare for a Taihape team coming off a well-needed bye as they try to bring themselves up to full strength.
Ratana coach Johno Kaa had promised hard drills this week to get them past their Achilles heel of fading away in games and making either physical or verbal mistakes in their frustration.
"The captain's [Vaan Rauhina] made it very clear [to stop that]," Kaa said.
"We had everything there [against Marist], but our discipline let us down in a bad way.
"The boys know where we fell over."
In the other games, Utiku Old Boys and Speirs Food Marton should be a tough clash at Memorial Park, while Dave Hoskin Carriers Marist will want to try to take some momentum from the win over Ratana when they play Wanganui Car Centre Kaierau at Spriggens Park.