In this case, the adjective serves to emphasize. Like "fluffy cat" – all cats are covered in fur, but this one is particularly so. "High Tower" – towers are generally built high, that's what towers are for, but this one is higher than the others.

Let's just say, not all cats are covered in fur (Canadian Sphynx). But all archers are ranged units by definition. Therefore, this epithet appeals to me much less than "long-range," which has only one drawback: that this quality is not yet commonly used to characterize troops. Moreover, this is not the only such word; there are also "armor-piercing" and "fire-piercing." All of them are ideal, except for this drawback, which is essentially a drawback of the language – its inability to express the desired concept. Usually, in such cases, either the scope of application of existing concepts is expanded, or words are borrowed from other languages. I chose the first option.

So, you have Titans, Atlanteans, and who else? If Thunderers are available, that would be ideal.

Mighty Atlanteans, Relentless Thunderers, Storm Titans.