My friend said he's <had a couple less cigarettes today> and even though it """"should"""" be <fewer>, I would NEVER say <had a couple fewer cigarettes today> in conversation.

Which one sounds better in your dialect? (conversationally; I don't give a poo about proper English)

Oh I guess I could've made this a poll but I'm more interested in why you'd prefer one over the other and where you're from! Sooooo... include that still!

Next stage of overthinking:

Consider <a couple less> & <a few less>. Do <couple> & <few> act as qualifiers that not only indicate the quantity of the noun but also that the noun is countable? Thus making <fewer> redundant?

<a couple less toys> = <a few less toys> = <fewer toys>

Searched a few English grammar websites for the applicable rules here and found a bunch like this, in case I was on the fence about whether prescriptivism often needlessly complicates and obfuscates communication.