I have a anchovy based tomato sauce (includes anchovies and anchovy oil) and would like to add clams. Seems like a good inclusion. Any thoughts ?

This is a classic taste combination - that is, the anchovies and the clams.
Some spaghetti with clams dishes use tomato sauce, some don’t.
Look online - there are many recipes. Some using clams cooked in the shell, some already cooked and canned.
See especially Geoffrey Zakarian or Serious Eats recipe.