It appears Philander Brown was in the 1860 Franklin Brown Company.
There are a few references to Philander at a Western Association of Leavitt Families website:
BURTON, GEAUGA, OHIO
… In Burton, they took up land in a beautiful forested area, cleared the land, built a home and began to farm. On a neighboring farm lived a widower, William Brown, and the three youngest of his nine children. Benjamin Franklin and Philander Brown would follow the Leavitts to Michigan and their sister, Emeline, would join them sometime after 1852 for the journey west. In Burton two events of note occurred…
4. CAMBRIA, HILLSDALE, MICHIGAN
… In 1845, the Leavitt family again turned their hearts and wagons westward, traveling to Cambria, Hillsdale, Michigan. They acquired land and began farming. Lucy Rowell Leavitt gave birth to her tenth child, who lived but a few months. Daughters Lucinda and Orilla married the sons of William Brown of Burton, namely Benjamin Franklin and Philander Brown. Sons, Josiah, Lyman Utley, and John Quincy Leavitt found their companions in Michigan. They became a close-knit, small community of families, much as the Leavitts had been in Canada. They farmed the land they had cleared. “They worked together there gathering sap from the maple trees and making sugar and maple syrup for market”. (From a John Quincy Leavitt history.) They helped construct roads in the area and worked on the Southern Michigan Raiload. John Quincy wanted to be a teacher and so he studied at Michigan College. We learn from John Quincy Leavitt’s history that “They were definitely an enterprising family, accomplishing almost anything they set out to accomplish.” John Quincy’s history tells us “they all wanted to go west together. They were delayed however, due to the untimely death of their father whose passing and burial beside his infant son, Thomas, in a Michigan cemetery made necessary the change of plans.” …
PARTIAL ROSTER FOR THE FRANKLIN BROWN INDEPENDENT COMPANY IN 1860 as found in the Historical Department of the LDS Church
Philander Brown
Orilla Leavitt Brown, wife of Philander Brown
Emeline Brown, sister of B.F. Brown and Philander Brown