I found a couple of threads after posting this that somewhat touch on this subject. I don't know why they didn't show up for me when I conducted my initial search. I may have overlooked them. However, rather than add an addendum to a long post, I'll try to summarize and synthesize them for an answer. Truth be told, they might be a bit too advanced for the level of the post I wrote. I am referring mainly to this thread here: [**How to decline adjectives modifying feminine nouns after 2, 3, 4?**](https://russian.stackexchange.com/questions/511/how-to-decline-adjectives-modifying-feminine-nouns-after-2-3-4) That post contains a comment with a link to another post that I now see is a bit irrelevant to my question(s), so I've omitted it, but you can access it by going to the link above. I'm referring here to an answer by [**Quassnoi**](https://russian.stackexchange.com/users/134/quassnoi) and I quote from it a bit later in this answer but most of it is unrelated to this post here. What follows are three points that address my question(s) in this thread. Please don't construe my attempt to answer my own question as a sign that I am not also interested in answers from others, especially those who can do so with specifics/details/cited sources. Most of my attempt here will be much broader in scope. --- 1) The general rules laid out at the top of the post that starts my thread here (Can anyone clear up ...?) should suffice in most situations. How do I know that? I don't. All I can tell you is that I've seen that rule in a pretty reputable Russian textbook and have seen several examples of where that rule is applied. Those that don't follow those rules appear to be the exception rather than the rule, but I haven't queried the entire Russian lexicon or even a scientifically measured portion of it (e.g., the first 100 most common Russian adjectives and nouns and all the many permutations of how they could combine with "2," "3," and "4"). It could be done, but it would take me a lot of time and I suspect that I would discover what the Russian textbook _ТРОЙКА_ has already provided me with its rule. 2) In the thread titled, "How to decline adjectives ..." (the one I mention earlier in this answer), the author of it (KCd) refers to the number-adjective-noun rules for feminine nouns. To refresh, it is this: ##Any adjectives placed between the numeral and the noun must be in the nominative plural if the singular form of the noun is feminine. KCd writes (paraphrasing a source): >**... this rule is "normally" true if the noun has the same stress in genitive singular and nominative plural ...** >**... if the noun has different stress in genitive singular and nominative plural then the adjective is "normally" genitive plural (e.g., три различных стороны).** To help visualize this and corroborate it, I've added a screenshot from Wiktionary:  This is good information to have, but it doesn't explain to me why I've seen so many instances of "две мировых войны." You can see from the image below that even though the form of the plural changes from nominative to genitive, the stress stays the same:  _Note how the stress from genitive singular to nominative plural changes, which is what KCd is referring to._ 3) This comes from Quassnoi's answer. A large part of it was in Russian, and, after using Google Translate, I realized that it doesn't actually address my question except for one thing and that is what was said in reference to a rule he was citing from a book by [**Dietmar Rosenthal**](https://en.wikipedia.org/wiki/Dietmar_Rosenthal) titled, [**_Справочник по правописанию и литературной правке для работников печати_.**](http://royallib.com/book/rozental_ditmar/spravochnik_po_pravopisaniyu_i_literaturnoy_pravke_dlya_rabotnikov_pechati.html) In reference to the rule referenced from the book, Quassnoi writes: >**This rule is not strict and is often violated.** And perhaps, _that_ can be said of any rule.