The way you describe it, it will look like you just got whatever you could find that day, on the shelf, at home depot and didn't plan ahead.

I like to keep all the plumbing fixtures and accessories the same brand/collection and finish. You can use a different complementary finish for sconces/pendants and mirrors.

At minimum, all the plumbing fixtures will look better if they are the same brand/design and finish.

I think mixed finishes can work beautifully in a bathroom when there’s a plan behind it. Matte black and brushed nickel are both neutral enough to complement each other. The key is keeping the look balanced — for example, letting one finish dominate and using the other as an accent so it feels intentional.