Daniel,
In light of increased susceptability to disease due to several factors such as soil chemistry changes - however slight - you're actually on the right path.
We set about 11 years ago looking at the environment these oaks were adapted to - what they successfully grew within and first tried to gauge whatever changes may have occurred over the 150-plus years they have become the principle hardwood growing in this region.
Standing back and seeing we were smack-dab in the foci of a disease epidemic, I had to travel beyond the areas of destruction out to the limits of the growing range of these particular adapted hybrids. Taking both soil and tissue analysis from the "healthy" stands and establishing a base-line level of what I determined to be normal nutritional levels, ran comparisons to levels found near here and witnessed some extreme deficiencies and major differences in both. That rang alarms that forced me to study what chemical influences may be responsible for soil levels of certain compounds to leach, bind, or disappear. Same with tissue samples within the tree - leaves, stems, and roots.
Next we gathered data from other areas of the planet that were reporting similar tree losses, disease epidemics, and studied their suspected causes. Historical losses in the United States in recent histories were the Adirondacs of the NE, pulpwood losses of eastern Canada, and most striking the Los Angeles basin but the most blatant reports came from Poland and eastern Europe, where all the correlating data pointed to the most similar factor in all regions - coal-fired powerplant and smelter emissions high in sulfur and nitric acids downwind from the disease areas.
Time to return to school. Learn about the chemical interactions in relation to soil chemistry, rainwater chemistry, runoff and point-source pollution effect. Then on to tree biology and nutritional requirements. ????, gathered a treasure chest of dire stuff. While the research schools were busy with funding earmarked for in vitro response for disease to antagonizing treatments per se, lots of information about what was actually killing AIDS patients was coming to light - learned that AIDS doesn't kill at all, but a repressed immune response does in effect by allowing any pathogen to grow unchecked. Most HIV infections eventually kill from pneumonia, rickets, and neoplasms that a functional immune system will generally manage successfully.
Chemo and radiation, often times death to the patient. Alamo and Arbotect, same thing. There's a better way but plant science in the U.S. has principally been guided by finding higher yields, more herbicide resistance, market research and stimulation, and pathogen management with attention paid to what kills a plant, not so much with what allows what kills a plant to become a virulent entity.