Well to answer the original question... Lots of handling issues with many many motorhomes (not just class A). You're driving a HOUSE not a sports car! :B
Getting it weighed and setting the correct tire pressure is the best start.
Slow & easy is the best pace to set for yourself.
After that you have lots of handling tweaks you can chase.
(On my old rig, a steer-safe & a Ultratrac rear trac-bar helped it the most.)
Search the
CHF and you'll find lots of info. Lots of drivers say they're really happy with it.
Should be doable on your own. (I still haven't done mine yet though.)
Although - I think the CHF helps most with the slower speed rock/sway of the rig.
But it all adds up to a better handling rig.
"Better handling" being the key phrase here.
Unfortunately, I think the biggest tail-waggin-da-dog problem on the smaller coaches is the short wheelbase.
I guess the ultimate fix is trading it in on a 40'r or DP. :E