Which preposition to use with contrivers

of Occurrences 31%

Tongue's accusing of Lord Essex, Lord Shaftesbury, and Lord Wharton, for the contrivers of the plot, and setting his father and Oates to act their parts.

in Occurrences 1%

He, therefore, in conformity with these feelings, could do nothing openly; all must be the effect of management; and as he thought Peter one of the best contrivers in the world, to his ingenuity he determined to refer the arrangement.

Which preposition to use with  contrivers