Holkans can choke and speed rush civs without copper. They're among the fastest guaranteed units in the game to hit with, faster than the dog soldier.
They are not faster than the dog soldier. Both are resourceless. Both cost the same. Holkan requires hunting and bronze; dog requires only bronze. I wouldn't attack cities with either but I've never tried the choking thing. Sounds like a real waste of resources. I don't like to destroy what I want to take.
BE to attack mounted in ENEMY territory? That's got to be a joke, right? I really hope you're kidding. This ability doesn't work vs mounted in cities. No stack, under any circumstances, should be field-attacked in its own territory, since it has double the movement of the BE.
Yeah I know. I sometimes encounter stacks of doom outside of cities in enemy territory.
Roads only have 2 movement at that stage so when you're in enemy territory and not adjacent to their city, you have a roughly 50% chance of finding yourself next to their stack of doom before it attacks you. I do attack the city I can get to fastest generally, but I do spend more time not adjacent to a city than adjacent to an enemy city when moving through enemy territory.
I don't see any reason not to take out their horse archers if your SoD is on defensable territory like a forest or hill. Especially if you have a woodsman healer. So you declare war and then wait for their stack of doom to come into your territory? I usually head for the city with their stack of doom provided there is a hill/forest path to it.
I wiped out an entire civ with holkans on immortal in one of the immortal U games. I lost the game afterward, but ONLY because I sucked at the time and wasn't ready for immortal. The rush itself was successful, and allowed me to expand to 14 cities. One probably wouldn't use them on deity except in 1 neighbor starts to choke-rush, but hell...a lot of otherwise sound UUs are weaker at deity.
The enemy on immortal, as you know, would normally hook up to copper before you can get a significant stack to their cities. But I suppose that could be countered with posting a pair of holkan on the resource, though I'm not sure if that would be fast enough, probably not reliably. I'm not a fan of early rushes on the difficulty I'm playing on now. But I admit I haven't tried a spearman UU rush. Never even crossed my mind.
14 cities early on immortal = no research. When I first started immortal I would play as victoria of rome, expand really fast like I would on emperor, and get vastly outresearched, and then lose. Now until I have courthouses and/or currency, the expansion is conservative, like half that many cities.
Holkans own barbs for a long time, too. Easily until axes show, and putting off archery until that finally occurs allows you to get more important techs first. They're also a GREAT UU for the AI, to screw with all those persia/egypt lovers out there (and potentially even quechas). They're a mid tier UU or so, way way above BE.
I'm not completely sure as I haven't tried what you suggested, but I would guess they're below average. Very rare not to have copper or iron in a game, except archipelago. And a rush that early wouldn't be economically viable most of the time unless you pack the map or happen to have somebody very close to you. But I still like the Maya as their UB is top-tier IMO.