The Parents of William F. Eichhorn, Post 2

In my research for more information on William F. Eichhorn's parents today I found the marriage certificate of Charles H. Eichhorme (Eichhorne?) and Catherine Wise in Chippewa, Welland, Ontario, Canada on 3 Sep 1871.  This appears to answer the Charles/Herman name question, as H possibly stands for Herman.  Witnesses were Leonard Wise (yay, possible relative!) and Miss Meyeir (sp?).  No parents are given for either and Germany is the only listing under birth place.

Welland County, Ontario, Ontario, Canada Marriages, 1857-1924 166, Eichhome/Eichhorne-Wise, 1871; digital images, The Generations Network, Inc., Ancestry.com (http://www.ancestry.com : accessed 18 Feb 2009).  

I then came across a register for Catherine Wise and Charles Herman Thorn on the same day and in the same place.  The ages are different and so are the witnesses, including a Jacob Wise (possibly another relative!).  The ages on this match those on the 1880 census, while those on the first do not.  Parent names and birth locations are fully given, which would make me very happy if this is the same (or correct) people.  With a thick German accent I could understand how Eichhorn could be heard as Thorn, although I have to admit this is not one of the spellings I had ever came up with.  

Welland County, Ontario, Ontario, Canada Marriages, 1857-1924; digital images, The Generations Network, Inc., Ancestry.com and Genealogical Research Library  (http://www.ancestry.com). 

I have found them in the 1900 census, but not in 1910.   He was born Dec 1848 and she in Apr 1849.  They had been married 28 years and she was the mother of 8, with 5 still living.  It says they arrived in America in 1852 and Charles was naturalized.  This date is obviously incorrect.

Additionally I found the listing for the marriage of George Eickhorn, son of Charles H. Eickhorn and Katharine Weise in 1900 at St. James Episcopal Church.

June Partridge Zintz, Marriages from Buffalo church records 1825-1900, volume 1 : transcribed from microfilm of English-speaking Protestant church records and compared with marriage license records in Erie County Hall, 1 (Apollo, Pennsylvania: Closson Press, 2004), 1: 70.  

This is where I need help:

I came across the WWI draft card for Frederick William Eichhorn.  Does anyone have information on whether families often named one child one name and the next the reverse, such as William Fred and Frederick William?

How can I figure out which marriage record is correct?  Could they both be for my relatives?  It seems like quite a coincidence.

Additionally, I have not previously done research in Canada, so any suggestions you have on further research are much appreciated.

Research I plan to do to find more info on them, prior to immigration to Canada:

1. Check with the Episcopal Church of Buffalo for records on the Eichhorns.  I have done this previously with the Whitehead family and found much information.
2. Check Buffalo city directories between 1900 - 1910 to try to narrow down death records.
3. Try to find Charles naturalization record for US.
4. Check for probate records for both in Buffalo.
5. Search for border crossing record in Niagara Falls.
6. Check Canadian census' 1851 - 1871 for them with their parents.
7. If the Thorn/Wise certificate is correct, try to figure out which Lutheran church they belonged to.
8. Continue to read the two books I borrowed on Canadian genealogy research, as it is new to me.