[PTTG]

A clone army doesn't need to be genetically identical (though that is a literal contradiction in terms, we usually use Clone Army to mean Fast-Growth Exowomb Produced Army).

If you have the ability to slip an exowomb device past enemy defenses, you can set up a troop growing facility within their territory, where you can produce soldiers that pass for human civilians. In fact, actually cloning enemy citizens helps you bypass their security apparatus.

Try doing any of that with robots!