The part of the sentence "shrewd man" is correct and usable in written English.
You can use it to describe a person who is wise and knows how to act to get what they want. For example, "The politician was a shrewd man, often finding ways to gain the advantage in negotiations."
Mallett is a shrewd man and he knows that.
Will is a shrewd man and a careful student of political philosophy.
Bob Willis, the former England bowler and Sky commentator, suggested the idea – what a shrewd man he is.
Shea, a shrewd man, had already seen what lay at the heart of the owners' resistance to expansion: pay television.
But he is a shrewd man and thoughtful, and he has a good vantage point from which to watch the debate as it is unfolding in Europe.
Dealers are shrewd men who know how to hold on to their money.
Calling him a "master politician" and an "autocrat, a shrewd and calculating man," the prosecutor, Christine Dahl, said that Mr. Seselj had engaged in poisonous propaganda that incited fear and hatred and that his fiery speeches in many towns and at the front lines spurred Serbs to kill, torture and rape in their effort to drive away Croats and Muslims.
Rupert Murdoch might be the shrewdest man ever to run a media company, and in selling up for a good price while his company faces structural threats that mean its value could be close to peak, he may be right to exit.
He describes himself as being a "shrewd, well educated and calculating man" -- not surprising for someone who was recently revealed to be the books' most important character.
His father, Tywin Lannister, is regarded as one of the shrewdest men in the seven kingdoms, and Tyrion, more than his sister or brother, inherited Tywin's intellect and instincts.
