CCA is important for chassis batteries - amp hours is what you focus on for the coach battery.
Some Class C RV mfg provide a single class 24 battery which maybe insufficient depending on how you use your RV. Many add a second battery. You can always get a bigger battery upgrading to type 27 or type 31 battery if space is available. Once again the focus is amp hours which might be 80 in type 24 increasing to 125 in type 31. Some replace the 12 volt batteries with two six volt deep cycle batteries which might provide 225 amp hours. In my case space (height) was an issue so my Class C has two type 24 which I purchase at Costco.