Aside from in his two wins, in provincial maiden and Class 1 grade, Arnaqueur has taken on some of the best of his age and far from disgraced himself but Dubois felt he wasn't getting serious.
"We didn't see the point of keeping him as a stallion, after a three-year-old season, when they're not Group 1 horses,'' he said.
"I think it was a benefit for him to be gelded. He looks like a better horse and is easier to handle now."
The form around him reads well for a Country Championships.
At just his second start he was beaten 1.9 lengths by Converge at Listed level, he finished four lengths off Captivant in the Group 1 Champagne Stakes as a two-year-old, and in five starts last spring he recorded a Group 3 placing in the Spring Stakes at Newcastle and two fourths at stakes level.
Tommy Berry, who won last year's South East feature and the final on Art Cadeau, partners Arnaqueur who has trialled just the once, for a close fourth behind Hilal, on January 31.
"He's a bit stronger now, mentally and physically, so we will see on Sunday. He has a good profile, he can settle down nicely in the race and is quite versatile,'' Dubois said.
"It's gone smoothly, we had one trial and could maybe have had a second trial but he had a strong gallop on Monday morning.
"He looks in good condition and I expect a good run.
"The draw is not a problem for him because he can be slow from the gates so it's better to be a bit outside and not too far in."
The Goulburn trainer won the South East Country Championships in 2020 with Julian Rock when the race was transferred from Nowra to Moruya and feels Arnaqueur certainly has more natural ability.
Arnaqueur was $4.80 favourite with TAB on Friday and is on the third line at $11 for the $500,000 Newhaven Park Country Championships Final (1400m) at Randwick on April 2.
Dubois has one other runner at Nowra in four-year-old mare Reelclass in the Go Steel Building Products Plate (1400m).
She's drawn 12 in the 14 horse field and that will make things tough, according to Dubois, but the extra distance is in her favour second-up after running fifth over 1000m at Goulburn three weeks ago.
"She's a handy filly and has a bad draw so I think she's only a small chance,'' he said.
