Thanks for your help, George and John.
My source for these two had found that both were killed in action in 1863. Then, I find them both on FindAGrave that shows David died April 18, 1863 and James died May 29, 1863. The really interesting and coincidental thing is...Bruce Nichols wrote in one of the Guerrilla Warfare books that a Patterson Crockett was killed at the Gabbert farm which was May 26, 1863. James' full name is James Patterson Crockett. And, as I just stated, James Patterson died on May 29, three days after the Gabbert raid.
Family genealogy has James Patterson dying in Centralia and coming back to Cedar for burial. So now, you have a Patterson Crockett that died on May 26 at the Gabbert farm and a James Patterson dying on May 29.
Here's what I was thinking...and it's a far shot I know,.....sometimes people went by their middle names instead of their first. And....sometimes, rarely, but sometimes, people would put a burial date on a stone instead of the death. So is it possible that Nichols' Patterson Crockett is the one in Cedar County and the genealogy had the death place wrong? Or...you have a Patterson Crockett and a James Patterson Crockett, two separate people, dying three days apart, both of them in action of some kind and both are Patterson?!
In researching my family. I have found men wounded in battle Shiloh and Chickamauga, that were sent home or to a hospital. In both cases they were sent to relatives homes and died there. That could be the case of your men. The records show they died far away from battle which that doesn't make any sense, but having complete or as complete as I can get I am able to determine where they were wounded and sometime the extent of their wounds. Being your ancestors were irregular troops that is a luxury you do not have. Good luck with your reserach , glad I was able to help you just a little bit.