Resistances are additive. But they don't act like an orifice. Many people like to think of electricity like water in a pipe and that doesn't always work. if you have a 14 gauge wire and a 10 gauge wire, theoretically it won't matter which order you put them, the result will be the same. I haven't tried this for audio.
A short piece of smaller wire may not be a problem. That said, it might. Many power conditioners do more harm than good. Many a good amp has been sold because the power conditioner or power cord was not supplying it the power it needed to shine.
Jerry