This is kind of a long shot, and I should correct myself upfront about Marguerite Ruch, who was registered in Dossenheim-sur-Zinsel, not Ernolsheim-les-Saverne. The family actually lived at the Zeller mill, which seems to have been in both towns at different times.
Also living at the Zeller mill in from 1818 until at least 1825 was a family named SOMMER or SUMMER (Joseph writes it both ways at different times). This is the family of Joseph Sommer/Summer, farmer, b abt 1775, and Anna Maria Garig (usually spelled GERICK in Dossenheim records). They didn't have a Philippe born anywhere that I can find, and their origins are hazy. A Geneanet tree says they married at Neuvillier, in Lorraine, which I don't find through a search engine. I thought it might be a slip for Neuwiller-les-Saverne, in Bas Rhin, but no record found there.
This is the link to a family tree for that clan. https://gw.geneanet.org/erinecraig?lang=en&pz=erin+eliza...
The interesting part is that this family, which disappears from the Dossenheim records, went to America. They lived in IL. OH, and IN, some in Allen Co, IN. I don't know the date of the Sommers' emigration; their last child here is born in 1825.
The Ruchs were still at Dossenheim in Feb 1832 when Adam Ruch is declarant on the birth of an illegitimate child born to his daughter (a curious case, since the marriage of Ruch and Gunseth does not officially legitimize this daughter, who must have been born before they married -- she's 27 in early 1832, and Ruch and Gunseth married in 1809 -- and I have never been able to find her own birth record. Most likely she was acknowledged by Ruch at the time of birth but it would be nice to know).
Thee's no Philippe in the family. There is a John, whose dates are given as 25 May 1813-25 Aug 1893, but no other information (only one marriage is shown out of 12 children (one is probably a duplicate), and several are shown as living till nearly 1900. It's possible that John is a Jean Philippe, though the data is somewhat discrepant. This family is probably Catholic, but it's not probable that they didn't know the Ruchs, especially since both lived at the Zeller mill.
The locations seem awfully jumpy to me, maybe the result of cut 'n pasting. People moved around, but these go from the Dordogne to Lorraine to Lampertheim on the Bergstrasse to Dossenheim, well before railroads. (I tried Lampertheim in Bas Rhin and found some female Sommer marriages there in years 6 and 10 of the Republic, but nothing to connect a Joseph.) The tree shows younger son Jacques as born May 1825 in the Auvergne, but his birth act is in Dossenheim. Likewise, Madeleine is said in the tree to be born in 1815 at Sommerthal, but Sommer and Gerick had a Madeleine b Mar 1823 at Dossenheim.
Whether this family is Lutheran or Catholic, I don't know. The name Joseph is excruciatingly rare among Lutheran farm families, but every Catholic household has at least one, so it automatically triggers an alert button for me when I see it. However, it looks as if he may not be native to northern Bas Rhin, so the name may not be an indicator at all. All of the other names in the family are the standard ones that were used by everyone. There's no Francois, no Antoine, no Therese, no Odile. This family may have been Lutheran after all.
I would suggest contacting the owner of the tree and comparing notes. This seems pretty coincidental, if that's all it is.
Hope this helps you!