Taliban means students. There's an Arabic word tālib, meaning student, and, if you make that into a Pashtun plural, you get taliban. This is because the Taliban were, originally, just a small group of religious students who wanted to clean up Kandahar. They then got carried away, as capering students often do, and invaded Kabul.
Class, on the other hand, means those called to fight. There was a Proto Indo European word *kele, that meant, shout. From that the Romans got the verb calare, meaning call to arms. The early Roman population were always getting called to arms. When there were calared, the male population would form up as a c[a]lassis, and set off to find some Sabine women to rape.
The Roman king Servius Tullius divided the Romans into six classes so that he could tax them more efficiently, and so classis then came to mean a group. A classis could still be a military group like an army or a fleet, in the same way that an English division can still be military. But class could just be a part of a whole. Thus a school or a society could be broken up into classes, and the animal kingdom could be classified.
Incidentally, the reason that they are classified ads, is that they are arranged by subject, just as the Roman subjects were arranged for battle.
The Inky Fool found cross-dressing was much less fun in Kabul