I want to give you another example from Turkish history. Talas war. Great Turkish cities to the east of the Caspian were raided by Arab armies and thousands of Turks were massacred. Conclusion? The entrance Islam of the Turks in a collective way was almost 200 years late.
Entrance of Turks to Islam had nothing, absolutely nothing to do with the Talas battle or Arabs, yes Turks sided with the Arabs due to war with the Chinese however they kept to their shamanist beliefs.
Turkish cities? as? Those massacres Arabs committed were mainly of Persian peoples, they were very oppressive. However Turks were mainly nomadic and lived well beyond the Transoxiana, the places you will mention had mainly Iranian populations.
Turks, Mongols and Persians were actually very lenient compared to Arabs when it came to ruling, Arabs till this day continue there assimilation policies no differently.
Another factor could be that in the Balkans, the rulers were mainly locals who were appointed and had accepted Ottoman rule where as Arab empires it was almost always someone appointed of Arabian origin from the peninsula, that is why Arab empires did not last long or recover like the Turkic ones. Ottomans governed the way the Romans did, conquer and appoint locals, so long as they pay taxes no problem.
I know that the muslims didn't force their religion on others only some rate cases bu I think the ottomans didn't do much preaching like other Muslims did in Malaysia and indonisia for example they both became muslim by the arab and other muslims traders
Mainly through Sufi's and such preachers, same in India, Pakistan, Bangladesh IMO the difference is these people's followed Buddhism, Hinduism, local religions etc which was far easier to convert then those following a well establish religion & theological traditions like Christianity or Judaism.