Here is the oldest document known speaking of a Sarcher :
Sarchère : F. Cne of Longuefuye - La Sarchière, 1404 (Arch. de la M. E) - La Sarchère (in all the texts) - La Charchère (Dict. topog.) - Fief and estate dependent of the Courans which include in 1490 : " house, land, meadow, garden, food, wood, fief, juridiction, seigniory, duties, cens, pension." Guy de Laval and Marguerite Machefer, in 1405, assign it a pension of "trois setiers de seigle" to l'abbaye de Clermont. - Were Mr : Macé Sarcher, 1405, 1409. - François de la Pommeraye, seigneur du Verger, buyer of Jacques Sarcher, 1490.[...]
Cab. Louis Garnier. Angot A., Abbé, Dictionnaire historique, topographique et biographique de la Mayenne.
We can ask ourselves which gives its name to the other. Father Angot, in the introduction of his dictionnary, gives us an element of answer :(I give here only a summary of the text because translation is not easy for me :-) )
Between the XIth and XIIIth century, a lot of lands were cleared. Most of the farms and domains created then, had a name derived from the name of the first owner with the finals "ières" or "erie". Before this age, the name of the farms were derived from a characteristic of the place: Ferrière is a place where there is a lot of "Fer" (Iron), Fromentière is a place with a lot of "froment" (wheat), ..
The construction of the names answer to logical rules : proper nouns that point to an occupation give names with "erie". For example, Maçon (bricklayer) gives Maçonnerie (bricklaying). All the others give names with "ière" : La Normandière, la Renardière, except if the name ends with "er" which give then "erie" : La Besnerie, la Gauterie, ..
As the name of the farm ends with "ère" (or perhaps "ière"), we can think that the farm is earlier than the clearing period. If it were the name of the person that gives the name to the farm, the farm would be named "sarcherie". Now we must find what was the signification of "sarch..."