Comprehensive car insurance covers damages from an "act of God," or events that are not caused by a car driving into something else. An "act of God" can include things like damage from a heavy tree branch falling on your car. Since you have no control over when or why a tree branch would fall on your car, this kind of accident would be covered under your comprehensive policy.
While not all large insurance companies are the same, some of them might be selling insurance policies for vehicles that they do not have much experience covering. RV insurance in particular is offered by many auto insurance companies who may not be well prepared for handling the intricacies of an RV insurance claim. When choosing who is going to insure your vehicle, make sure it is a provider who specializes in RV insurance—regardless of its size—or that at least has a good track record of dealing with RV insurance policies and claims.
USAA only sells policies to current and former members of the military and their families and is consistently rated at the top of its class by A.M. Best with an A++ financial strength rating. It doesn’t have an official customer service rating with J.D. Power, but USAA is noted by J.D. as providing “claims satisfaction and shopping satisfaction”. A perk of USAA is if your uniform is damaged or stolen in an event your policy covers and you are on active duty or deployed, USAA will reimburse you without you having to pay a deductible.