I've tested 3600, 3600X, 3700X and 3900X. All 3600, 3600X and 3700X had similar temps (even though there are 2 cores difference) while the 3900X had 6-7°C more using the same coolers. I was testing whole Noctua coolers line and some more like Scythe or other brands, but of course I wasn't using the smallest coolers on the 3900X but something like U12S or D15. It really doesn't matter much on any Ryzen 3000.