I would suggest the opposite.
From personal experience I can tell you that if you put the carbon filter first it will plug up prematurely.
8+ years full time I have experienced the nasty hard water full of calcium, iron and sulphur in Northern Arizona to water pumped from a creek in Washington taught me a lot about dealing with water quality issues.
I would suggest that you reach out to Jesse at Waterfixers in Oregon. He is a sharp guy and can point you in the right direction.
2004.5 Dodge 3500 5.9 Cummins, NV5400, 5" turbo back stainless exhaust, Edger programmer & 22.5 Alcoa's
2002 Forest River 36 5th Wheel (staying home)
1992 Jayco 29 5th Wheel (Mexico veteran & headed back)
2002 "faux" Wanderlodge 40' My new toy....