Match the speed and timings, not the brand.

No.

You don’t need the exact same model number or brand. You do need the same DDR generation (DDR4 vs DDR5), speed (e.g., 3200MHz), and CAS latency (e.g., CL16). If those match, your motherboard will run them in dual channel and they’ll work fine together most of the time.

The risk is that different brands or even different batches of the same brand might have slightly different internal chips, which can cause instability at higher memory speeds. But in practice, if you buy a stick with the same frequency and timings, it usually works. Your BIOS will just default to the slower stick’s