To take full advantage of WT-2767, we'd like to make sure that every time we create scenarios in the test suite, we call number_scenarios(). We already require that check_scenarios() be called, and that is called by number_scenarios(). Some tests call number_scenarios(), some call check_scenarios(). In addition, there is multiply_scenarios to combine multiple scenarios into one.

This feels confusing, and is certainly inconsistent. I'd propose a single function: make_scenarios() that takes one or more scenarios as arguments, calls multiply_scenarios(), then check_scenarios(), and finally number_scenarios(). In the tests, get rid of all the other calls, and consistently call make_scenarios(). This will touch most of the test/suite files.