Complex sentence: Any Ottoman soldier who committed a significant deed on the battlefield could be promoted to the Silahtar division, although normally members of other mounted units, like Timarli Sipahis or one of the other less prestigious of the four divisions of Kapikulu Sipahis, were promoted this way.
Split into simpler sentences: Any Ottoman soldier who committed a significant deed on the battlefield may have been promoted to the Silahtar division. Although usually members of other mounted units, like Timarli Sipahis or other less prestigious four divisions of Kapikulu Sipahis, were promoted this way.