There are a few hundred nouns of the second declension in Russian that do not have a nominative plural in the expected -ы but rather in -а, e.g. город-города. This ending is also invariably stressed.
I've noticed that for multisyllabic nouns with this plural, the stress in the singular virtually never falls on the last syllable. Thus far I've found only a single exception, рука́в-рукава́.
What is the reason for this?