canonical is meant to handle duplicates. Differing telephone numbers, price tags or alike make two pages unique, even though they ma not be interpreted as high quality content.
As far as I understand you have a kind of an overview page A describing a service/busines.
This page links to pages b, c, and d.
All of them contain either 80% of page A + 20% unique content OR page A contains 80% content that is assembled by the contents of pages b, c, and d.
Let's have it a bit more visual: the colours represent content. Same color means, same content.
In either cases a
canonical is not the weapon of choice as it only indicate a relation like d
Page A is unique. Also are pages b, c and d. Only e (built just for clarification) is an exact copy of d and therefore we can use a
canonical. The decision in which direction it has to pint ( e > d or d > e is up to you)
[…] we think it would be appropriate to have rel=canonical on each child point to the parent.
If you put a
canonical on b, c and d pointing to A only A would be interpreted as the unique page that should be indexed and ranked.
Further, the 20% unique content on b, c and d that differs on all pages may lead to the
canonical being ignored.
I want to make sure the children pages are indexed and searchable via search engines as well because they'll have important info such as each locations address, phone, and unique stats.
Therefore you do not need a
canonical you just have to make sure they can be crawled and indexed by linking them properly.
You can improve the importance of all pages by adding further individual information. At the end of the day this is the way a lot of category/product pages in shops are structured.