"the earlier ones" is correct and usable in written English. You can use it when you are referring to something or someone that has come before, or to compare or contrast something or someone with something or someone that has come before. For example: "The newer cars are more efficient than the earlier ones."
This result generalized on the earlier ones in the literature.
This result improved on the earlier ones concerning the exponential decay.
The current protests share one quality with the earlier ones: their unpredictability.
"We're converging on a model where later dispersals swamped the earlier ones," he says.
The earlier ones, "Firebird" and "Petrouchka," were historic triumphs.
Each ill-advised trip and appointment amplifies the earlier ones.
"I like the earlier ones better," Karina admits.
"The earlier ones are human, the later ones abstract.
The earlier ones were in 2004 and last May.
I'm really enjoying how his series references the earlier ones.
Two opinions discuss the merits of the controversy; the last affirmed conviction upon the earlier ones.
Ludwig does not simply clarify my doubts with English writing, it enlightens my writing with new possibilities
Simone Ivan Conte
Software Engineer at Adobe, UK