Anknown

I have the option to get Corsair Vengeance RGB pro 3200 CL16 or the Corsair Vengeance RGB pro 3600 CL18 for almost the same price (3$ difference). However, my board supports only 3466 Mhz. Which one should i pick? The 3200 CL16 kit or the 3600 CL18 kit with underclock, maybe enough room for improved timings? I never did RAM underclocking for tighter timings. My CPU is Ryzen 5 2600.