What elevated Marist's chances is the likes of veterans Brown, Koro, and workhorse No8 Ryan Gill have the ingrained ability to spot an opportunity before it opens up.
Gill punished Taihape when running in the channel off the ruck, while Brown and Koro sparked Marist's three tries with pinpoint passing and taking on the line.
Taihape finally put it together late in the piece when Marist subbed their playmakers and tried to sit on their lead, but the home side's second converted try came on the shadow of fulltime.
Now on a bye week, they have lost the coveted Top 4 spot and given up a lot of ground to the other contenders.
"No attack. When it looked like we were setting something up, turned it over," said coach Kerry Whale.
"We will have to bowl a couple of big teams next round."
Gilbert was definitely missed, as he would have looked to keep Gill honest, although prop Hadlee Hay-Horton and lock Hamish Bennett did their best to fill the void.
"We've got a big enough squad though, we should cover it," said Whale.
It was disconcerting to see normally reliable figures like Dane Whale, Jaye Flaws, Cyrus Paringatai and Paora McCarthy struggle with their timing and cohesion out wide during the first three quarters.
Meanwhile, Marist had talent to burn on the bench and did not let their own errors and infringements keep them from the task at hand.
"We needed a [winning] game, obviously," said coach Jason Hamlin.
"We were asking for effort and we got that today, but execution let us down a bit.
"It shows what kind of team [Taihape] have been the last two seasons that they came back."
He agreed the talent of Brown and Koro to find something from nothing was vital in a scrappy match.
"They are plugging it. Our young boys are doing all the running stuff, but the old guys are doing the key stuff."
Lock Sam Madams adds another dimension with his physicality up front, not withstanding his sinbinning in the final two minutes when Marist were trapped on their tryline.
After a virtual forceback game in the opening minutes, Marist were the first to actually utilise the territory gained, as Koro took on the line, and then from the ruck Brown spotted the gap and shot through.
The halfback looked for support before backing himself to go around fullback Glen Horton to score.
First-five Mitchell Millar was given two penalty opportunities and landed the second for 10-0 after 20 minutes.
Dane Whale replied with two penalties for 10-6, before Marist counterattacked through Gill, Brown and winger Simon Dibben.
Spreading to the other sideline, Koro hit a perfect cut-out pass to winger Luke Foster, who was just stopped at the corner flag, but the Marist pack rumbled inside and Madams dived through.
Millar added his third penalty late in the third quarter, with Whale making an immediate reply, before Marist appeared to seal the game after the pack drove from a penalty lineout, and then the ball went through the hands for Foster to cross untouched.
Finally galvanised, Taihape controlled the ball on both sidelines, as Dibben just prevented McCarthy from scoring.
The home team came back the other way and Hay-Horton got his delayed pop pass to Bennett, who ran in at the corner and went around to improve Whale's kick.
Flanker Jack Kinder went blindside and then nearly scored in the in-goal from a grubber kick chase, as Taihape camped in Marist's 10m zone.
Following a series of team penalties, Madams was binned and Kinder took one of several free taps to dive low and bring his team a bonus point with time up.
Marist 26 (S Brown, S Madams, L Foster tries; M Millar 3 pen, 2 con) bt Taihape 23 (H Bennett, J Kinder tries; D Whale 3 pen, 2 con). HT: 15-6.