As far as a pagan Turk in central Asia is concerned, Ali is Iranian. Just like St Peter is Spanish to a 16th century Aztec.
Timur should know better, having been born and raised not on the steppes but in the relatively sedentary culture of Islamized Central Asia.
The failure of Turks to settle in cities AND retain their culture in central Asia continues long after the 1300s. Tajikistan takes it name from such a phenomenon, Tajik originally meaning "Arab" before meaning something like "settled people" (See Frye, Golden Age of Persia).
IMHO, it's more like settled Turks adopted elements of both Turkish and Iranian/Islamic cultures, rather than becoming completely Iranian, especially between AD1000 - AD1400 when Turks had just arrived in the Islamic lands, becoming urbanized and in many cases set themselves up as a separate ruling class.
That would be debatable to any pre-modern person. (I'm assuming you are Australian) Your failure to regard yourself as English is the result of your geographical location and a globalised world of clearly divided sovereign states.
Actually, my failure to regard myself as English is due to the fact that, ethnically, I'm not English and in fact descended from Chinese immigrants. My point was, just because someone speaks a language, doesn't necessarily mean he is ethnically or often even culturally part of a particular group.
Timur also spoke Turkish, Chagatai and IIRC Mongolian (correct me if I'm wrong). He was a well-urbanized man undoubtedly influenced by both Turkic and Persian cultures. However, the trouble with justifying him as a Persian leader stems these - he was not ethnically Persian, and the rest of Greater Persia (apart from Transoxiana) did not see him as Persian. His rule was highly destructive to Persia save for Samarkand, which makes him a poor choice if one is to include him as a "Persian leader".
Islamicization is a form of Persianisation as far as central Asian Turks are concerned.
Central Asian Turks had been Muslims for a almost three centuries before Timur was born. Islam was pretty much a part of their cultural identity by then.
Debatable and of marginal relevance. Most states have peripheries and cores.
In this case, the core of the Timurid Empire consists only of Transoxiana. The rest of Persia is on periphery.
There isn't much reason for this discussion, beyond us both learning why the other wants/doesn't want Tamerlane as a Persian leader.
Indeed.
