The phrase "a difficult group of" is correct and usable in written English.
You can use it when describing a collection of individuals or entities that present challenges or complexities in understanding or managing.
Example: "The project was challenging due to a difficult group of stakeholders with conflicting interests."
Alternatives: "a challenging set of" or "a tough collection of".
"As you know," they said in a statement, "this is a difficult group of people to manage.
"These are a difficult group of people to deal with," said Dr. Herbert D. Kleber, the medical director of the National Center on Addiction and Substance Abuse in New York and a professor of psychiatry at Columbia University, who is familiar with the study.
Although GPs still viewed CPP as a rare and new condition, and as a difficult group of patients to manage, they were, however, empathic to the suffering of women with these symptoms.
With greater than 10 year follow-up in the first two HRA designs, and with excellent results in a difficult group of patients, there are proven designs of HRA available for surgeons willing to undergo the training to become specialist resurfacing surgeons.
Although our response rate compares favourably with other surveys of physicians (a difficult group to engage in participation), 37 38 39 it was lower than that of other web based surveys of clinical trial investigators.
This is, however, a difficult group to recruit as co-occurrence of both conditions is rare.
This was a return to the sort of sloppiness that this young team appeared to have left behind during their impressive dominance of a difficult group, although, in fairness, much of their erratic finishing appeared to be borne of over-exuberance in a festive home stadium rather than the nonchalance of the past.
This was not a particularly difficult group of people to find," says Tony Wood, creative director of Lime Pictures.
This is a taxonomically difficult group of very similar species.
Wins against Bayern and against Roma in Rome to negotiate a difficult group suggested they were coming of age and coming to terms with the demands of the Champions League - but a timid first half here revisited old doubts.
Instead the side that are seventh in Ligue 1 flourished in Europe, finishing top of a difficult group.
