Tensorflow is a must if you wish to play some games currently in development. It can be used also for many other things, like machine learning for the neural networks behind the scenes of games, helping games improve by literally making their AI smarter, or developing AI yourself.
Action games and run & gun games rule so when using Ragnarok Mobile you'll be doing a lot of shooting. Run and gun games need more RAM. You can free some RAM by disabling DSP, but some games already use all that RAM and it's not the same as using more RAM.
It doesn't really matter which games run better on which emulator, as you can change the emulators later. For now, just focus on getting the games to run. To run either emulator, just download and run the binary. Rasberry Pi 2, Raspberry Pi 3, and any other can be used to use either emulator.
Yuzu has much better frame rates than Ryujinx on most games. It also has a better feel and controls than Ryujinx. For full details on how to run Yuzu, check out the Raspberry Pi 2, Raspberry Pi 3, and Raspberry Pi 4 versions of the guide.
Head over to GitHub to find the latest versions of each ROM. Since Yuzu is pretty new, there hasn't been a lot of testing of it. DO NOT update the most recent version found on GitHub, as there is a known issue which will cause Yuzu to stop working. This is extremely annoying because this issue has yet to be solvable. d2c66b5586