An important thing to remember, it's not like these jeeps were driven into a lake. Flood water is contaminated with all sorts of nasty stuff from industrial waste, vehicular fluids and raw sewage. Getting the moisture out is one thing, getting the crud out with it can be an entirely different task. It can be done, but will it be worth the time and effort?.
Grit, sand, mud, dirt will get in to every nook and cranny, and ruin nearly every electrical component, and likely most of the drive-train too.
Even if I had all the time in the world to complete a total rebuild, I still wouldn't do it. I could accomplish it with the exception of the engine and drivetrain, but I just won't want to devote the time and effort to try to make it run again.