Are you sure the reference to narrow thureoi is specifically concerning the class of soldiers called euzonoi? As I recall, Polybios says that most of the Achaians fought in with thos weapons prior to the Philopoimen reform. Does he call them "euzonoi" in that passage?

But no, I wouldn't connect them with our thureophoroi, and certainly not with our thorakitai. They're probably closer to our peltastai than our thureophoroi, though its even possible he's referring to soldiers outfitted similarly to our iphikratous hoplitai (though I'm a little doubtful in that regard). we may not have a really suitable unit for that sort.