Counterpoint: -copter is a perfectly cromulent suffix. https://en.wiktionary.org/wiki/-copter

gyrocopter, helicopter, quadcopter, hexacopter, octocopter, parcelcopter, and—most famously—

roflcopter, https://en.wiktionary.org/wiki/roflcopter#/media/File:Roflco...

They all have their own dictionary entries.

Octocopter makes perfect sense. Everyone understands immediately what it means, and that's the only purpose of language: to convey ideas. It should be clear, which this is, and concise, which this is.

Fidelity to ancient Greek is not, and should not, be a goal for English.