Yes, but I also think it isn't a bad idea to separate your applications. Just because each application is a monolith doesn't mean that all of your code has to be in one repository.
Can your admin system be a separate system? Can they be three separate systems because three separate groups will use them? Even if you don't immediately split them into separate repositories, it may make sense to segment them as if they were, because if successful, you will start running into problems at around 40 programmers.
Can your admin system be a separate system? Can they be three separate systems because three separate groups will use them? Even if you don't immediately split them into separate repositories, it may make sense to segment them as if they were, because if successful, you will start running into problems at around 40 programmers.