is the savory tart from nice, pissaladiere, too salty?

To make pissaladiere less salty, you could reduce the anchovies and/or use less salty olives. This recipe from chefjune https://food52.com/recipes/14243-pissaladiere-a-la-rabe uses broccoli rabe in addition to the anchovies and olives. You can see in the recipe that she recommends different olives. I’m not familiar with all of them, but I’m guessing some are saltier than others. Good luck!!

I've had pissaladiere and liked it.
But saltiness is a personal preference and, for some, a health issue.
Looking at a few recipes just now, I see most have about 2 anchovies per serving and various amounts of olive.
Perhaps try a recipe from a reliable source (James Beard Foundation, Julia Child, The Spruce Eats, various French bloggers in English or French, various reliable magazines - Bon Appetite, Food and Wine).
Do a test run.
Make dough as instructed. Add toppings per recipe to one side, and half the measure to the other side. Bake and taste. See which you like better, and which you think customers would like better.