Short answer is that yes, I would bet on 6 ARC Sizer + 6 PPC Seater working just fine. I might not guarantee it without checking my own 6 PPC seater, but I’m 90% sure it will reach short enough.
What brass are you planning to use? A lot of guys are buying what factory ammo they can find just to get brass to reload - brass has been pretty tough to find. A lot of guys are making brass from 6.5 Grendel and x39, with varying processes and varying success.
I’m out of town all weekend coaching wrestling, but I can check when I get back Sunday night or Monday if my 6 PPC seater I use for 243 LBC (6mm Grendel) will sink the seating plug deep enough to get into 6 ARC. I would bet heavily, yes.