McCarthy in Lissane and Tooreen, Caheragh

I am very stuck trying to sort out my Grandfather's ancestors in Lissane and Tooreen, townlands in Caheragh parish near Drimoleague. If anybody knows anything about these families, I would be very grateful for clarification. Just having a few family trees would help.

My web page of family documents is here:
http://www.sjbar.com/irishGenealogy

and my Granddad's paternal line is in this chart. His father was Humphrey Michael Collins, or "Humphrey Mickey" as the family calls him:
http://www.sjbar.com/irishGenealogy/michael_collins_descendants.jpg

Humphrey Mickey Collins went to the farm of his bride Margaret McCarthy. He migrated presumably from Lower Lissane to Tooreen. I was told she had "many sisters" so maybe there weren't enough men around to farm it.

I have been told that Ellen McCarthy was a sister of Margaret's. I am not sure she was a sister, perhaps she was a niece. From searching LDS film I believe Ellen was born in 15-Sep-1869 in Tooreen. Her father was Cornelius and her mother was Mary McCarthy McCarthy. Ellen married Patrick Maher in 1903. My family knows definitely that she was Ellen McCarthy Maher.

Since Margaret was likely born before 1864 I cannot conveniently look up her birth record on film until I have the opportunity to search RC baptismal records. But her death record in 1906 says she is 44, which would put her birth year at about 1862. I would err on the side of the census underestimating her age.

Ellen's marriage record says her place of residence at the time of marriage was Tooreen and that her father Cornelius was a steward. A Maggie McCarthy and a John Couglan witnessed the marriage. They marriage took place in the Caheragh chapel.

On Humphrey's and Margaret's marriage record it says Margaret's residence at the time of marriage was Upper Lissane and that her father was also a Cornelius and was a farmer. (If they were from Tooreen and she and Humphrey ended up in Tooreen, I have no idea why she was staying in Upper Lissane.) A Daniel McCarthy and an Elise McCarthy witnessed that marriage. They were married in the Killeenleagh chapel.

There IS a Margaret McCarthy born to a Cornelius and to a Mary Collins according to the IGI. This would have been in 1863, she would be the right age for my family tree. But the problem is, this Margaret had a sister Ellen born in 1854 who married a Florence McCarthy and I think they emigrated (I've corresponded with her granddaughter). It's a different Ellen. Other siblings in this family were Andrew (1856), Jane (1858), Mary (1860) who married Michael Kiely, Dan (1862), and Cornelius (1866). This Cornelius could not have fathered Ellen McCarthy Maher.

From the 1901 and 1911 census records, I know that Margaret McCarthy's mother was also named Mary and she was living in Humphrey's and Margaret's household helping to take care of her grandkids.

So I am dealing with maybe three or four different Cornelius McCarthys, different Mary McCarthys (wives of Cornelius), too many Ellens, and too many Margarets, and they are all in Lissane and Tooreen.

In desperation I have started searching the rolls of birth registers, year by year. So far I have found the following nuclear family:

Daniel McCarthy and Mary Walsh
children (I have found so far):
Margaret b. 12-Mar-1870 (film #101204)
Charles, b. 29-Sep-1872 (film #255865)

Maybe this Daniel witnessed Ellen McCarthy Maher's marriage but I don't know who Elise was.

Oh, and there is a John Collins born 2-Feb-1872 in Lissane to John Collins and an Ellen McCarthy. Yet another Ellen. For other reasons I believe that this family is also in my family tree, but I've already dumped enough in this post so I won't go into further detail about this.

I am going to keep searching the films all the way back to 1864, as I cannot seem to find any clarification otherwise.