The phrase "adversarial groups" is correct and usable in written English.
It can be used to describe factions or entities that are in opposition or conflict with each other, often in a competitive or hostile context.
Example: "The negotiations broke down due to the presence of adversarial groups, each unwilling to compromise on their demands."
Alternatives: "opposing factions" or "conflicting parties".
Or, what if adversarial groups of humans develop competing A.I. systems that get along no better than their inventors do?
The détente not only made life in downtown Tampa less daunting, but gave two traditionally adversarial groups a chance to redefine their relationship.
Another PowerPoint presentation prepared for Hunton & Williams said the research that HBGary Federal and its partners could do for the law firm on behalf of the Chamber of Commerce would "mitigate effect of adversarial groups" like U.S. Chamber Watch.
But the fact that two contiguous and occasionally adversarial groups in Manhattan have established second identities in the same small town, 60 miles away, on parallel streets, totally by accident, is a serendipitous phenomenon of another order that even Neil Simon couldn't dream up.
Mr Gates, who served under presidents Obama and Bush, told the BBC that was because they were made up of "historically adversarial groups".
They tend to be arbitrary and often awkward, splitting kin groups across different countries while placing adversarial groups within the same borders.
Spectator sports are ideal; adversarial group activities are the best.
So this was a case where the US government - through affirmative steps and/or approving acquiescence to criminal, sophisticated cyber-attacks - all but destroyed the ability of an adversarial group, convicted of no crime, to function on the internet.
Mr. Koch, a billionaire industrialist who made his fortune in fossil fuels and whose better-known brothers underwrite conservative political causes, has been fighting the wind farm, called Cape Wind, for more than a decade, donating about $5 million and leading an adversarial group against it.
Disturbed about the influence of the Society of the Friends of the Blacks, the colonists established an adversarial group called the Massiac Club, which claimed the right to be represented in the National Assembly.
With half a billion dollars in public-sector marketing budgets coming under his discretion, the fiery former Army captain is threatening to slash ad buys with adversarial media groups, striking at the financial foundations of Brazil's free press.
