Absolutely and no idea why they dont. I much prefer Arca Swiss and converted my Manfrotto heads to Arca Swiss. But looking around what other pros use and what's on the floor of the stores I visit, I see a lot of Manfrotos, so my guess is they can also do the reverse, put an RC2 style on the bottom of OEM feet. To make things more incoherent, Gitzo, which is a brand of Vitec and made on the same factory as Manfrotto sells Arca Swiss-style.But if they make the feet Arca-Swiss compatible, they still have the standard thread on the bottom to attach other feet such as Manfrotto. So it does not detract in any way from the usability of other brands but ADDS the value of not having to buy a replacement for those of us who use Arca-Swiss style. Obviously Tamron and Sigma feel it adds enough value to their telephotos that they are willing to do it.