Parent-child slug path sections but in two different URL formats

[develyma]

I'm unclear on what's best to have something for slugs/SEO with parent-child relationships for pages and/or posts (whichever works best for the content),but I'm imagining something like this (where the "long" version is categorically sensible but probably not user-friendly, and the "short" version is prettier but may have too much ambiguity):

1. URL path for States: /state/[state-name] like california or new-york which will show content for that state
2. URL short path for Cities: /city/[city-name] like st-louis which will show content for that city (probably infeasible)
3. URL long path for Cities: /state/[state-name]/city/[city-name] like /state/new-york/albany which will show content for the city
4. URL intuitive short path for Cities: /[state-name]/[city-name] like /california/los-angeles which will show content for the city

#2 is simplest but some cities share names and I'd rather not append the state for duplicates like [city-name][-state-name], that seems silly.

#4 seems best but I'm wondering if some cities in the same state share names, and then I'm not sure how to handle that other than appending [-#] like rochester-2. I understand that the same issue could happen with #3. This is probably just a secondary concern.

I suppose it'd be nice for SEO to have a long slug version and a short slug version, maybe where one directs to the other, but I'm just weighing readability against SEO and user friendliness.

Also, I'm not sure whether to use Pages or Posts for this.

I'd prefer to not create a Page or Post for each State and City, which could have their own templates by "type" (of content?). Much of the content for each "type" ("State" type and "City" type) would be static and formatted fin their own way, but each state and city page of course would have their own specific informational content mixed in. I'm unclear on how to store any specific state/city content without having to create separate pages/posts for them, if possible. Sorry, I'm deviating a bit into content now as opposed to slug formats, but they may be interrelated in wp-admin or a plugin or custom code or whatever.

I feel like there's relatively simple solutions here but I'm not quite sure how to do it in default wp-admin at this point (which I'd prefer to use before trying a plugin).

Anyway, advice much appreciated.