Asked and answered, I think. Consider the ride you get in a Jeep compared with a Town Car. Car compared to Motor Home. Go-Kart compared to Jeep, etc.
You can stiffen up a coach's ride to a point. If you aren't planning on placing a whole lot of miles on the coach (and most of those on the highway), then IMO it's more of a want than a need.
To get specific, I haven't seen any coaches with numbers in the mid 40s (nor am I an expert). There's a current thread about Monaco Cayman handling, and their ratio is right at 50%
Rick and Sandy
2003 American Eagle, 46K miles
...from Sept 2015