Even a small difference in orbits adds up over time. You don't need much fuel for orbital adjustments, as long as you're staying in the same plane.
Say one satellite's orbit is a bit smaller. That means that, over time, they will naturally drift farther and farther apart, until they end up on different sides of the globe. At that point, just raise the smaller orbit slightly.
Kerbal Space Program is really good for understanding stuff like this.
You just described the way I launched my first comms network constellation[0] - basically loaded a whole bunch of satellites on a single rocket and deployed them on slightly different orbits, so that they'll spread themselves out as the time goes.
Only mid-launch I figured out I could just put three of them on Kerbisynchronous Equatorial Orbit at 120° phase difference :/.
Yes, KSP is absolutely amazing for learning this stuff :).
[0] - useful if you're playing with RemoteTech mod, which prevents you from operating unmanned spacecraft if they don't have a radio connection back to a proper command centre.
Say one satellite's orbit is a bit smaller. That means that, over time, they will naturally drift farther and farther apart, until they end up on different sides of the globe. At that point, just raise the smaller orbit slightly.
Kerbal Space Program is really good for understanding stuff like this.