Maher is a former jumps jockey with the wild man looks, while Eustace is the more softly spoken Englishman who joined him in partnership in 2018.
The odd couple have created a giant racing machine, one that will only be fuelled by yesterday's win.
They have embraced sports science like few stables before them, using GPS data from trackwork to tell them what the eye sometimes misses.
They have 180 staff and won more than A$28m in stakes last season and have even gone as far as appointing a chief executive to run the business of being a racing stable.
Their combination of training Group 1 winners in everything from 2-year-old races to Australia's biggest jumping events has been like catnip to their ownership base. They can buy almost any horse they want to train and it will be snapped up.
While Gold Trip may have come from Europe, the hardened jumps jockey and stockman still remains in Maher and he has a soft spot for New Zealand-bred horses, so it wouldn't surprise to see him at the Ready to Run sale at Karaka in two weeks.
So the trainers who held the Cup aloft at a showery Flemington yesterday are the embodiment of the future of Australian racing: big business practices applied on a huge scale to the age-old skills of horsemanship.
Horse racing always has been an often bitter cocktail of luck, genetics and the undefined will to win, so there will always be a place for equine oddities and small-time trainers.
Clayton Douglas proved that winning the Everest in Sydney just two weeks ago with Giga Kick.
But as the yearling and tried horse markets continue their booms, the biggest, most glamorous and modern stables will take an increasingly stronger stranglehold on its best races through weight of numbers and their ability to bring together vast ownership groups.
This spring has been dominated by them, Chris Waller winning the Caulfield Cup and Victoria Derby, James Cummings the Cox Plate and now maybe the stable that will eventually grow into the most powerful of them all has the Melbourne Cup.
There was still joy for the Kiwis in this Cup though, with Emissary finishing second for ex-pat trainer Mike Moroney, again with a horse purchased out of a Horses In Training sale in England in 2020.
And third-placed High Emocean, also trained by Maher and Eustace, is a New Zealand-bred mare who was one of the luckless stories storming home late to finish in front of favourite Deauville Legend, who loomed up to win at the 600m but his weight and first attempt at 3200m told.
A pre-race favourite Smokin' Romans — one of six New Zealand hopefuls in the field — finished seventh.