Quoting: "A word of advice. If you just purchased this memory, and for whatever reason you bought two separate sticks of the same memory instead of buying them together in a matched set, see if you can return them for a refund or credit towards buying a similar or same set of matched sticks that come together in a kit. It is ALWAYS better to have matched modules because from brand to brand, or even within the same brand, in fact, even when the part numbers are IDENTICAL, there can be anything from simply slightly different memory chips that were sourced from different bins at the end or beginning of a production run to entirely different configurations altogether even though the model numbers seem to be the same. Some manufacturers even reuse model numbers when they discontinue a product. Point being, memory is only the same for sure when all sticks came out of the same blister pack or packaging and were sold as a tested kit."
Iif you are asking if 4 identical piece of RAM can work as quad channel using their XMP profile, the answer is yes. Different brand, or same brand different timing may cause problems, agree.
At the same batch (in general RAM bought at the same time at the same place) probably would be very much identical. There is a small chance that they would not be identical. But it is a way small chance.
And if you live in a place where you can find 4 piece of RAM packaged together good for you, it is almost not possible for many places.