Viktor Dankl had a long and storied career with the Austro-Hungarian forces. It seem fairly reasonable to assume that this ExLibris was probably designed by Emil Ranzenhofer for this Viktor Dankl as their paths could have crossed any number to times during their respective careers. Viktor Dankl attended the War School in Vienna in the 1880's while Emil was also in Vienna attending art school.
Viktor Dankl spent time mapping the Tyrol and, just before the outbreak of WWI, was the Commander of the XIV Corps in February 1912 with responsibility for the Austrian Tyrol. Emil Ranzenhofer spent a great deal of time in the Tyrol and often considered his Tyrolean artwork his finest.
Emil Ranzenhofer spent time in the Tyrol while working as an artist for the Krigspressequartier and in early May 1915 Viktor Dankl was transferred to the Southwestern front to assume the command of the Tyrol's defences. With weak forces he successfully halted all Italian attempts to invade the Tyrol.
Thus, is seems quite probable that Emil Ranzenhofer did in fact design this Dankl Exlibris specifically for Viktor.