Redfish will take a lot of different patterns. That's been my experience. But they are moody and sometimes they have lock jaw.
I like to have a fly that gets down on the bottom and creates little puffs of mud. A lot of patterns fit this. Weighted clousers, redfish crack, various crabs, some shrimp flies, redfish Ritalin. But if you fish around submerged grass an unweighted or lightly weighted fly is better. Seaducers, bead chain weighted flies.
I like noise making patterns in murky water. The Avalon Permit fly is an example that works on redfish in muddy water.
Main thing is to get The fly in their feeding zone. Easiest way it to put it ahead of their path and twitch when they get close. That's how I got my first slot red. Most flies I use for reds are size 2 through 8. Lighter and more streamline flies cast easier than heavy bulky flies.