I usually recommend only one outside board.

我通常建议只担当一家公司的外部董事。

youdao

Besides Hogan, two Japanese, from the insurance and securities industries, were picked as outside board members.

NPR: Former GM Executive Tapped For Toyota Board

Hennessy says that his outside board work has made him a better president.

NEWYORKER: Get Rich U.

Obviously, if an operating executive is going to be on an outside board, one outside board is better than three.

FORBES: All Operating Executives Should Never Serve On Any Outside Boards