Sky/Dun,
I have had the opposite with Fescue. If it weren't for crabgrass the cattle here would have starved. I loved the old fescue but it seems the newer fescue doesn't hold up to drought near as well or at least that is my experience. The old would turn brown and come back when the rains came just like you talk about Dun.
Here is how I handle, location SE part of West TN, fescue for best results:
I like to plant in the fall and late as rainfall has been unusual the last few years. This gives the roots time to get a good hold before spring and really lets it take off. I don't like to cut it for hay the first year or let it get shorter than 4"-6" from grazing. My experience with this is that if I break either of those two rules a minor drought(Now typical) will cause a 10-15% loss and a major could cause up to 40% loss. I don't have the ability to switch pastures but I'm averaging about 2 acres to 1 cow/calf pair so it isn't getting pushed.
Like anything there are so many variables and management styles as well as location that can change results.
Usually crabgrass takes up the spots where the fescue dies. I like to sew clover the following fall over a heavy frost/freeze or snow. Has worked great for me.