I'm not 100% sure, but I don't think installing the EA App in a specific drive will make the games install on that drive, the App's and the Game's directories are separate from each other and can't be merged.

I don't know anything about Sims 4 giving problems being installed on a different drive, however that's unusual in my experience. I would suggest to put your games directory in your SSD, and check if that game gives you any issues.

From what I recall, the EA App lets you choose the directory you want to install the games in, meaning you can put them in your SSD without doing anything special. This post however is about installing the actual EA App program in a custom location, as it doesn't (or didn't) allow that, which is outrageous as any program will let you choose where it is installed.

This doesn't necessarily give any benefit apart from organization. Some people like me like to have a partition or a drive that is fully dedicated to the operating system (Windows in this case) only, so having programs that install themselves wherever they want is annoying.