Use the ones that fit your needs, and test them in Report-only mode first. The templates are generic, they cannot account for the needs of all customers. Best view them as sort of recommendations from Microsoft, but apply them with your specific needs in mind.
For example, the "Block legacy authentication" template is certainly something to consider as it will improve your security posture, but you might have dependency on legacy software, multi-functional devices, scripts and other types of automation that still leverage basic auth. Similarly for any templates that force MFA, make sure that the users in scope will not be affected first. But do aim to enable those in the nearest possible future, those are highly recommended.