Happy with my RX 7900 XT.
Pro-tip. A custom resolution of approx 3624 x 2038 will give you around 90% of the pixels of 4K resolution, or you can just use an in game resolution scaler. In Warhammer III, I can run at 90% of 4K (Ultra Preset) and get 1% lows of 64 in the battle benchmark. For some reason, the in game resolution scaler gives me a bit better framerate than a custom resolution in this game.
If you have an RX 7900 XTX, I'd guess that 4K resolution wouldn't be an issue in this game.
It's nice to know that my PC isn't CPU bottlenecked, as I can get 1% lows of 67 FPS in the CPU heavy 'Mirrors of Madness' benchmark (when the resolution is scaled down), which has a ton of units and things going on.