Cortex A7 vs cortex A53, isn't that straight forward to compare based on clockspeed or core count alone.
That said, my guess would be that the rt3200 is probably going to be faster (maybe even considerably so, maybe just a bit), there's no alternative to testing both - or opting for some other solution (depending on the desired performance, quite a few options if integrated WLAN support isn't needed; e.g. nanopi r4s, RPi CM4+dfrobot baseboard, x86_64, …).
Any x86 will be much more powerfull in term of computation. So your critera should be electric power consumption. There are some CPU with low consumption (10W, even 7W).