Chicken really needs to be pressure-cooked before dehydrating, which is why Sarbar/Sarah on her trailcooking.com site recommends using canned chicken to dehydrate. Even canned chicken is unsatisfactory if you don't break up the chunks into tiny pieces before dehydrating. It works better if you give the completely dehydrated chicken a few whirls in the blender to break it up even more.
Ground beef works, but it not only needs to be as low-fat as possible, you need to remove as much fat as you can after cooking and before dehydrating.
Both meats will still have some crunch after rehydrating, but will taste good.
Lots more info here:
If you need a lot of dried meat, you may find that freeze dried meat bought in bulk is no more expensive than buying and dehydrating high quality chicken and ground beef. However, this only is true if you need enough to use the biggest packages of freeze-dried meat.