Phones with keyboard(s)

ESLearnerDo I say 'phones with keyboards' or 'phones with keyboard'?

phones with a keyboard
(unless there actually are phones with more than one keyboard)

So is it more appropriate to say phones with a keyboard_ or _phones with keyboards?

How I read it is, phones with keyboards meaning multiple phones with multiple keyboards while phones with (a) keyboard means multiple phones sharing one keyboard. Although the second phrase needs an article, determiner, or number if keyboard is to be singular.

phxsunstoonHow I read it is, phones with keyboards meaning multiple phones with multiple keyboards That meaning is not clear.
while phones with (a) keyboard means multiple phones sharing one keyboard. Does that situation even exist???

This is from the "Princeton Grammar Guide."

"Nouns connected to singular pronouns or nouns should also be singular; nouns connected to plural pronouns or nouns should be plural.

For example: All of the men wore dresses.
All of the men wore a dress. (incorrect)

See the confusion stirred up by the violation of this rule? In the latter example, t

No one is going to think that all of the men shared the same one dress at the same time.

Even though it is common sense, anything that might interrupt the sentence flow should be avoided.