A 50-0 win over Ireland in Limerick on Saturday night ensured the Kangaroos checked out of the group stages with a 100 per cent record and their statistics are getting better as time goes on.
After a 28-20 victory over England first up, they saw off Fiji 32-2 and then the Irish, giving a warning to the United States ahead of their quarter-final clash in Wrexham next weekend.
And Sheens thinks their improvements are coming owing to a studious approach to fine margins.
"We are happy. We set ourselves some goals and the boys achieved them. Our kick-chase game was excellent and that was what we really worked hard on this week," Sheens said after the nine-try rout at Thomond Park.
Asked if he had been using plays he had reserved for the last eight, he added: "There's a bit of that. We played nice and tight but got a little bit excited near their line in the first half.
"We weren't worried about a score, even though we put a score on them, but at the end of the day it was about making sure we were disciplined and making sure our kick-chase is there for the bigger games."
Sheens' next task is to work out who will face the Americans. The coach has rotated his pack over the last fortnight and Saturday night's win was achieved in the absence of Darius Boyd, Greg Inglis, Matt Scott and Jonathan Thurston.
Inglis and Thurston are almost certain to return, meaning that Daly Cherry-Evans - excellent against Fiji and Ireland - may have to drop to the bench.
Sheens had admitted that he has given himself a headache but was quick to reject suggestions his men have been given an easy ride in the group stages.
"They have broken a sweat, don't worry. It's a little harder than it looks I think you'll find," he said.
"We had some timing issues (against Ireland) and I blame myself for that because I have changed the halves, had two full-backs and given the halves a couple of runs. They're as cranky as hell about that and I know they're all competitive.
"But we have led our pool and I think we can play better, we will improve that. We have got here and played well as a team."
- Sports & Recreation