Flour protein and browning
Changing the protein content affects the dough and the eventual crumb (when cooked).  So the question shouldn't exactly be how does protein more protein/gluten affect browning, apart from the increased gluten will give you are more flexible dough which you work with more (ie thinner).

The two ways you can increase the crisping/browning of your pizza is: 


Roll/stretch out your dough thinner 
Placing your pizza on a pre-heated skillet before either placing into a hot oven, or better still using a broiler to apply a high heat from above.  This will increase temperature on the base and topping.