I read somewhere that like 90 percent of brake noise complaints come down to missing or dried up lube on the backing plates and slide pins, not the pad material itself. The pads get blamed because they are the part you can see, but the grease is what lets everything slide and float like it should. Cheap grease works fine as long as it is the right kind, the silicone stuff for the pins and a little on the shims and ears. The other thing is cleaning the bracket before you lube it, because new grease over old rust and dust does nothing. So no, you are not overthinking it, you just skipped the step that actually keeps things quiet.