Best practice on creating a launcher/updater for a bigger app on MacOS? We have 2 applications: a small launcher/updater, somewhat like the Steam client, and a bigger app which is started from the launcher.

Right now the launcher downloads the big app inside its own Contents and starts it from there.

The launcher/updater and bigger app cannot be merged into a single app as per design requirements.

The problem which we're facing is that in some cases we need to overwrite the launcher completely and when we do this the bigger app inside it gets removed. 

We want to avoid removing the bigger app when we're overwriting.

We're considering a few solutions but are unsure which approach is the best:

1) Create a directory in /Applications, so that we have /Applications/MyApp/Launcher.app and /Applications/MyApp/BiggerApp.app

2) Install the big app in the Library dir so that we have /Applications/Launcher.app and /Library/MyApp/BiggerApp.app

Approach 1 has the advantage that all the files are in a single location so if a user wants to remove the app he can just delete that directory.

Approach 2 has the advantage of not creating a directory for our app inside /Applications but the downside is that if a user wants to uninstall he'll have to remove the dir from /Library as well.

What is the recommended way of storing 2 interdependent but separate apps?
Best practice is to include the app in the package contents of the launcher.
As you said this can't be done, the second best solution would be to create a folder in /Applications. There are various apps which do this; most famously done by the Adobe suite, but there's others like MAMP.