Are Merced Medina and Merced Macias the same person Calvillo , Ags. 1800's

Calvillo, Aguascalientes church records have me believing that they may be the same person. The names Merced Medina and Merced Macias come up in records naming her as a parent or grandparent. In some records she is called by Medina in another record Macias. I have been unable to clear up the relationship. I only have my suspicions.

Concider these conflicting entries.
Matrimony of Diego Serna and Marcela Lopez , June 11 1829
Diegos parents Juan Manuel Serna and Merced Macias

Diegos' and Marcela childrens entries of Grandparents are as follows

child Grandparents names
YSIDRO b. 03 Apr 1830 Juan Cerna and Merced Macias
JACINTO b. 15 Aug 1831 Juan Cerna and Merced Macias
SOTERA b. 21 Apr 1833 Juan Cerna and Merced Macias
Clemencia b. 22 Nov 1835 Juan Cerna and Merced Medina
Ysabel b. 02 Jul 1837 Juan Cerna and Merced Medina
Juana b. 23 Jun 1839 No entry
Jacinta b. 16 Aug 1841 Juan Cerda and Merced Medina
Siriaca b. 17 Jun 1843 Juan Cerda and Merced Masias
J. Refugio b. 01 Jun 1845 Juan Serda and Merced Medina
Manl. Adrian b. 08 Sep 1847 Juan Serna and Merced Masias
Bruno b. 09 Oct 1849 Juan Serna and Merced Masias
Nasario b. 26 Jul 1852 Juan Manl. Serna and Marcela Lopez , I am thinking this Marcela Lopez is a clarical Error as Marcela Lopes is the Mother not the grandmother.

Jose Manuel Serna and Trinidad Aguilera childrens entries of Grandparents are
child Grandparents
Crecensio b. 29 Dec 1805 Juan Serna and Merced Macias
Anto. Gil b. 01 Sep 1813 Juan Manuel Serda and Maria Merced
Manl. b. 15 Jun 1826 Juan Cerna and Merced Medina

IN the marriage of Casimiro Saucedo and Anastacia de los Dolores Serda m. 03 Feb 1799 . Anastacias's parents are Manuel Serda and Ma. Merced Macias.

In the decendants of Matias Serna and Juana Esparsa

child Grandparents
Jose Anto. b. 04 Aug 1814 Juan Manuel Serda and Merced Medina
Jose Pablo b. 07 Jun 1826 Juan Cerna and Merced Medina

The Serna, Serda , Cerna , Cerda variations dont bother me .. its the confusion of Maria Merced and Maria Medina . I need some clarifying information. Thanks in Advance. my contact info is Mooskies4 at aol dot com