How do you pronounce "English Speakers"? Do you treat sh and s as similar consonants?
As an American native English speaker, the adjacent "sh" and "s" are both pronounced and would be heard by those who grew up with English. Yes, the sounds are related, but that does not imply the sounds should be merged or one of them skipped. In fact, if one tried to merge them, the person might sound like they are slurring their words, possibly inebriated.
The sounds are distinctive enough to be key in a common tongue twister:
She sells seashells by the Seychelles seashore.
What makes it tricky to say is that one's tongue desires to transform some of the lone "s" to "sh".
As a non-native English speaker who is a lot around natives and non-natives, "sh" and "s" are different sounds, both of them enunciated and distinguishable.
Since in my native language those two sounds are coded to very different spelling patterns (sibilant associated with S, SS, and Ç mainly; and fricative associated with CH and SH mainly), there is not much of a tongue twister.
According to my German colleague - Disclaimer: I don't speak any German, it's his account, not mine - the spelling S (as in Strasse) is pronounced fricative, so he frequently mispronounces words spelled like "Speakers" when he has never heard it out loud.