Complex sentence: Some served competently, such as Charles E. Sawyer, the Hardings'personal physician from Marion who attended to them in the White House, who alerted Harding to the Veterans' Bureau scandal.
Split into simpler sentences: Some served competently, such as Charles E. Sawyer, the Hardings'personal physician from Marion who attended to them in the White House. Sawyer had alerted Harding to the Veterans' Bureau scandal.