Civ is heavily rooted in a certain "classical" view of history, in which generals' tactical brilliance is what determines history.
So I understand why they wanted to make room for actual tactics.
If that comes at the cost of archers being able to shoot a bunch of gatling gunners across the English channel without them having the reach to shoot back, then so be it.
Gatlings are just a borked unit. A simple upgrade completely changing the unit-type raison d'etre is simply a Bad Idea, I honestly don't understand why they did it like that.
So I understand why they wanted to make room for actual tactics.
If that comes at the cost of archers being able to shoot a bunch of gatling gunners across the English channel without them having the reach to shoot back, then so be it.