Many things have already been said but I would love to hear responses from people who have this type of land. Pawpaw can live after water has went over them! What you can’t plant is cherries and grapes. I personally find some callery pear rootstock very resistant to water but not all of them. I think persimmon can be water resistant but not all of them are it depends on genetics just like the callery pear. If I can offer advice go to similar locations and get your rootstock from a location that floods a lot. @39thparallel and I have dug up callery from an area with constant standing water. In addition to my other advice don’t think these highly resistant rootstocks graft the same as other trees because they are genetically unique. There are scrubby apple trees I know of that tolerate water though I can’t recall their name but they live in near standing water conditions like the callery pears I told you about.