In the following are the arguments for choosing PLS as the statistical means for testing structural equation models (Urbach & Ahleman, 2010) by the researchers, which may help you to defend your methodology selection.
PLS makes fewer demands regarding sample size than other methods.
PLS can be applied to complex structural equation models with a large number of constructs.
PLS does not require normal-distributed input data.
PLS is able to handle both reflective and formative constructs.
PLS is better suited for theory development than for theory testing.
PLS is especially useful for prediction.
PLS can handle first and second-order together.
Based on Chin, (1998a): In the latter case, PLS is used to develop propositions by exploring the relationships between variables.