Er, minor quibble: the area we know as Afghanistan today was conquered by and incorporated into *deep breath*:-
The Ummayads (from everywhere in the Arabic world), the Abbasids (Iran), the Tahirids (Iran), the Saffarids (also Iran), the Samanids (native Persian but based primarily out of modern Uzbekistan), the Seljuk Turks, the Ghurids (probably Sasanid Persians and while I've got your attention could someone mod in the Minaret of Jam please?), the Khwarazmians (mostly Iranian again; there's a bit of a theme developing), the Hulagu Ilkhanate (secessionist Mongols), the Timurids (of whom y'all may have heard), the Mughals (though bits of Afghanistan were under Safavid control at the time), and then being fought over by Russia and Great Britain as part of the Great Game.
You misuse the term "Graveyard of Empires", basically. In more modern history, yes, your use is accurate; the fact that Dr. Watson is an Afghan War veteran in both the original Sherlock Holmes books and the modern-dress BBC TV adaptation is proof enough of that. However, when you go further back it refers to the inability for empires to keep the Afghans pacified for very long, rather than not be conquered at all.
All this aside, I actually agree with you. A Graveyard Of Empires is a wonderfully evocative name, but it really doesn't fit with the UA TP's cooked up.
My suggestion remains Farrukh Nama, after Khushal Baba's poem of the same name about a dialogue between the pen and the sword, but it appears to have gotten lost in the thread. Hopefully it's an acceptable choice. =]