It could well be useful to have that guide accessible in the Category page but you might want it to rank as a separate page. People that search for "Paris Hotels" you would want to go to your category page but for "things to do in Paris" or "best areas to stay in Paris" or even "travel guide paris" you might want your guide page to rank but the person could well be considering hotels etc also.
Number one, I understand that the example you gave is an example. So I'm going to illustrate my point using your example.
The example shows two separate user intents. Mixing the intents may result in a poor outcome. Google rank the appropriate page for the appropriate query. Google does not tend to rank pages with mixed topics. Below is the full explanation, with actual queries to show the accuracy of the explanation.
In your example, people who search for Paris Hotels may show a preference for a page that lists and ranks a group of Paris Hotels. It's possible to show specific hotels if those hotels are super popular.
I wrote the previous sentence BEFORE checking the SERPs. If you check the SERPs for hotels in Paris
you'll see that I am correct, that's exactly what Google does, because it's matching the user intent. This is100% true (and written before checking the SERPs):
Google will NOT show pages that are about "travel guide Paris" for a hotel query. That's because those are two different search intents.
People who search for travel guides are people who may already have booked their flight and hotel and are looking for things to do, places to eat.
So if you mix the two together, it's at the risk of not being exactly what users want. The result is your page that mixes two user intents may not rank.
Do a search for Travel Guide Paris and you will see that I am 100% correct. There is no Hotel user intent.
So, perhaps not the answer you're looking for, but maybe the answer you need is that there may not be a good reason (for user experience or SEO) to drop an irrelevant article into the page.
Although the two pages are about Paris, they are not relevant to the user making a specific query. Relevance is always, always, always about relevance to the user, not the words.
Good luck and all the best to you!
:) Roger Montti aka martinibuster