The phrase "already in control" is correct and usable in written English.
You can use it to indicate that someone or something has gained authority or management over a situation prior to the current moment.
Example: "Despite the chaos, the team was already in control of the project and ensured everything was on track."
Alternatives: "already managing" or "already overseeing".
Already in control of Congress, the Democrats seem poised to take the White House.
The Republicans, already in control of the House, are four seats away from taking control of the Senate.
"There can be no 'mopping up,' because that term implies that we are already in control of the situation," he said.
The army is already in control of seven of eight West Bank cities, which it seized six weeks ago after back-to-back suicide bombings in Jerusalem.
Both times, Cairo's presidential palace was left untouched because in both cases the army was already in control of it by the time the presidents were formally ousted.
The fear of inadvertently supporting an Islamist takeover is delaying efforts to reconstruct the state where insurgents are already in control.
The second time point was p4, when myelination had already started in control mice and was already evidently impaired in Dicerfl/fl Dhh-Cre+ mice.
In 1889 the colonial government, already in financial control, assumed direct operational control by abolishing the Board and placing the College within the Technical Education Branch of the Department of Public Instruction (now the New South Wales Department of Education).
Nav Canada, the privatized Canadian air traffic control authority, already specializes in control of airplanes where there is no radar, notably in the North Atlantic.
By then Spain were already well in control and leading 4-0 with Silva, Torres and Villa all finding the target in an eight-minute spell.
Extramedullary hematopoiesis, which was already substantial in control pregnant animals, was increased after BBP treatment.
