Just a heads up, it the AMD Ryzen 2400G, not 4200G.
The i3-7350k was largely considered a "worthless" CPU, but emulators like Dolphin are one place where it actually makes sense and is extremely likely to be faster CPU-wise than the AMD Ryzen 2400G.
GPU-wise I'm no expert on modern Intel integrated graphics, but it should be more than enough to run games at 1x IR and 4x AF (which would visually match the GameCube and Wii), however I've no idea on its capabilities on running Ubershaders (which would likely run considerably better on the 2400g).
Also I believe that Dolphin does not support the anti-flicker filter that many games used as a sort of cheap anti-aliasing, so that combined with your use of an actual PC CRT monitor (which tend to be crisper than CRT SDTVs) may very well mean that you'll end up with worse aliasing than an actual GameCube or Wii actually exhibited. Therefore, even when running your CRT at something like 640x480, you may actually want to either increase the internal resolution or increase the anti-aliasing and/or anisotropic filtering anyway, all of which will increase the GPU load but I've no idea how much would be too much for the i3 iGPU.
One thing to keep in mind regardless is that fast dual-channel RAM can improve integrated graphics performance, and since anti-aliasing usually taxes video memory, I would imagine that higher bandwidth DDR4 would also help in that case.
The i3-7350k was largely considered a "worthless" CPU, but emulators like Dolphin are one place where it actually makes sense and is extremely likely to be faster CPU-wise than the AMD Ryzen 2400G.
GPU-wise I'm no expert on modern Intel integrated graphics, but it should be more than enough to run games at 1x IR and 4x AF (which would visually match the GameCube and Wii), however I've no idea on its capabilities on running Ubershaders (which would likely run considerably better on the 2400g).
Also I believe that Dolphin does not support the anti-flicker filter that many games used as a sort of cheap anti-aliasing, so that combined with your use of an actual PC CRT monitor (which tend to be crisper than CRT SDTVs) may very well mean that you'll end up with worse aliasing than an actual GameCube or Wii actually exhibited. Therefore, even when running your CRT at something like 640x480, you may actually want to either increase the internal resolution or increase the anti-aliasing and/or anisotropic filtering anyway, all of which will increase the GPU load but I've no idea how much would be too much for the i3 iGPU.
One thing to keep in mind regardless is that fast dual-channel RAM can improve integrated graphics performance, and since anti-aliasing usually taxes video memory, I would imagine that higher bandwidth DDR4 would also help in that case.
Dolphin 5.0 CPU benchmark
CPU: Pentium G3258 @ 4.5GHz 1.24v
GPU: Intel integrated
RAM: 4x4GB Corsair Vengence @ DDR3-1600
OS: Linux Mint of some variety + [VM] Win7 SP1 x64
CPU: Pentium G3258 @ 4.5GHz 1.24v
GPU: Intel integrated
RAM: 4x4GB Corsair Vengence @ DDR3-1600
OS: Linux Mint of some variety + [VM] Win7 SP1 x64