However, there is a limit to the extent to which other species can be used to compensate for income from lion hunting as homogenization of the trophy product among countries may compromise the viability in less popular and accessible countries [12].
http://plosone.org/article/info:doi/10.1371/journal.pone.0029332#article1.body1.sec4.sec4.p1

As mentioned above, there is no consideration of a substitution effect in Lindsey et al's model. We know of no study that has empirically tested substitution between species. The cited reference, Lindsey et al (2006), far from suggesting removal of lions would "homogenize" the hunting product, shows that lions are a less important species to the industry than buffalo, leopard, kudu and "rare antelope". In fact, this source emphasises the importance of buffalo to the industry, a finding which echoes (coauthor) Booth (2009), who found:

"Trophy buffalo are the most important species driving the economics of the hunting industry in southern and eastern Africa since" (p15)
"Hunting packages for plains game (i.e. trophy bags that do not include any of the dangerous game) is the bread and butter of privately operated game ranches and farms in South Africa, Namibia and Zimbabwe, and is highly competitive" (p16)

Booth, Vernon R. 2009. A Comparison of the Prices of Hunting Tourism in Southern and Eastern Africa. Joint publication of FAO and CIC. Budapest.

Lindsey, P. A., R. Alexander, L. G. Frank, A. Mathieson, and S. S. Romanach. 2006. “Potential of trophy hunting to create incentives for wildlife conservation in Africa where alternative wildlife-based land uses may not be viable.” Animal Conservation 9 (3) (August): 283-291.