I don't see anything too "generic" about the "1881 Census of Canada". Further details about where the specific record within that source can be entered in the Citation detail box.
The citation can be divided into two parts:
1) Where can the info be found?
2) Transcriptions (or summary) of info within the source.
Question one is answered in the Source Information and also in the Citation detail. For example, the Source info can have the name of a book, author, publiciation data, repository, etc. Whereas the Citation detail can have the location within that source, ie page number of a book, or the state, county, township or city, page number of a page in a census.
Question two - how much of info from the source should be in the citation versus in the actual details of a person - is a bit more of a judgment call. How are you going to present this data? In a web tree, or a published book, ie in an genealogy (register) report? If a printed report, FTM has the additional drawback of putting info from the source in the citation (the citation detail box) because, if chosen to be printed, it will be in the middle of possibly hundreds of pages of endless endnotes that will be difficult for the typical reader to refer to.
Or, do you simply want more info "on top" where you can see it in FTM, without referring to citation details, which are "buried" one level down from the Person Tab. Maybe you want that info visible at a glance as you are moving from person to person.
For example, you referred to a summary of a census, which I don't have in front of me for exact details. I use a rather standard format which is "10 yrs old with parents" or "54 yr old, wf Mariah-52, ch Frank-14, James-12, Matilda-10, carpenter, RE=$5,000. I now enter these items in the Description Field of the Residence Fact I am using for the census. I put a summary of pre-1850 census data counts in the Fact NOte for that Residence Fact. Many years ago, I put that info in the citation details box of the citation. Then, I saw where I was constantly referring to it later as I reviewed people and needed it visible "at a glance" as navigated through Person Tabs. Also, although I don't print many genealogy register reports on paper anymore, having that info buried hundreds of pages away in endless endnotes was a real problem for me.
Now I rarely use the citation detail box at all. Where I do, it is often an informal note to myself and I uncheck the box to print it. For example, yesterday I was entering by hand information from a County History for a man, his wife, parents, in-laws, and children into my file. I used the page number for the Citation Detail. I made a scan of the pages as pdfs and saved as Media to the citation. I sometimes transcribe the article, which I put in the Fact Note section of a custom fact I call "Bio-Note". In the citation detail section of the citation I put "John Doe Sketch" and then I unchecked the box to print that. The citation only needs the page number in order for a person to find it, but I want "John Doe Sketch" to be seen by me when I am looking at this citation in the records of his father-in-law.
I am putting more and more information directly into the sketch of the person, whether it be in the description field of a fact, or in a Fact Note, or in a completely separate fact (eg occupation from a census, where parents born from a census) and less and less in the citation detail box, which I hardly use at all anymore.