Looks like Kohei Arihara's posting is pretty much certain: https://www.mlbtraderumors.com/2020/11/nippon-ham-fighters-to-post-kohei-arihara.html
I don't see him as a difference maker, personally. The stuff is solid, but pretty average as far as MLB starters go, and the control/command comes and goes frequently. When he's locating, the slider and splitter are deadly, but you could say that about pretty much anybody. He's famous because he was a highly heralded prospect who finally "put it all together" in 2019, but really he just had a fantastic first half and fell off hard in the second. It's the longest stretch that he's pitched really well in his career, and he looked like pretty much the same old streaky guy this year. He's one of those guys who will often look unhittable for the first half of an outing and then just meltdown in like the 5th. I can't see him as more than a back-end guy in MLB.
Anyway, figured we could put these all in the same thread since teams tend to have philosophies/strategies for dealing with NPB imports, so a lot of the team rumors on these guys will probably look similar.
Expecting to find out if OF Haruki Nishikawa and SP Tomoyuki Sugano will be posted soon, especially if the Hawks continue to clobber the Giants and end the Japan Series in a couple days.