It's not clear that his forté was only plodding, stolid attacks.
Sure it is. He said as much himself. The book COLOSSAL CRACKS goes into detail about his way of war.
What isn't clear is why anyone would criticize him for not being willing to gamble the lives of his men the way other, "flashier" generals were.
There is no doubt Montgomery had a healthy opinion of himself and his abilities, which tends to muddy the waters in discussions about him. It's amusing to note that the last 4 or 6 weeks of his time commanding 8th Army in southern Italy is absent from his memoirs - a period that Advancing Fire is now exploring with their Orsogna project. One does note however that in place of an analysis of their failure to breach the Winter Line in late 1943, he reproduced a two page poem about his winter coat instead.
But as for "plodding" - not only does he admit it but he is getting more credit for doing it, since a rational analysis of the resources available to 8th Army and later 21st Army Group leads one to the conclusion that it would have been foolish not to rely on the overwhelming amounts of artillery and air support they enjoyed, and the numerical advantage in tanks, particularly in the face of severe shortages of trained infantry reinforcements.