Sorry, I got the title wrong.

In Vanilla+ (1.75), how large do enemy attacks eventually become, regardless of pollution?

Hello! Good question. To answer that we can look at 3 things: 1) The unit-group runtime size limit setting, 2) the current formula for determining the base size of the attack groups that form independently of pollution, and 3) the active cloning layer/formula.

• 1) Defaults to 200, but can be increased up to a maximum of 1111.
• 2) formula: local limit = math_min(max_unit_group_size, 1 + selected_difficulty.value + selected_difficulty.value * selected_difficulty.radius_modifier * (1 + selected_difficulty.radius_modifier * math_random(1 + selected_difficulty.value)))
• 3) formula: times_cloned = math_floor(((clone_settings["group"] or 0) + selected_difficulty.value) * (evolution_multiplier + (((clone_settings["group"] or 1) * selected_difficulty.value) * (evolution_multiplier or 1)) + 1)

tldr: approximately 140 units on Vanilla+

More complete answer:

2) Works out as follows:

local max_unit_group_size = 200 (default)
local selected_difficulty.value = 1.75 (Vanilla+)
local selected_difficulty.radius_modifier = 1.25

> limit = math_min(200, 1 + 1.75 + 1.75 * 1.25 * (1 + 1.25 * random(1 + 1.75)
> limit = math_min(200, 2.75 + 2.1875 * (1 + 1.25 * random(2.75)
> limit = math_min(200, 2.75 + 2.1875 * (1 + 1.25 * 2)
> limit = math_min(200, 2.75 + 2.1875 * (1 + 2.5)
> limit = math_min(200, 2.75 + 2.1875 * (3.5)
> limit = math_min(200, 2.75 + 7.65625
> limit = math_min(200, 10.40625)
> limit = 10.40625

10 actual enemy units

Active group cloning layer:

local clone_settings["group"] = 1 (default)
local selected_difficulty.value = 1.75
local evolution_multiplier = ((1.75 ^ (evolution_factor / (1.75 ^ (evolution_factor / 1.75)))) * evolution_factor)
> evolution_multiplier = 1.5 (maximum value at evolution_factor 1)

> times_cloned = math_floor(((1) + 1.75) * (1.5 + (((1) * 1.75) * (1.5)) + 1)
> times_cloned = math_floor((2.75) * (1.5 + (2.625)) + 1)
> times_cloned = math_floor(2.75 * 5.125)
> times_cloned = math_floor(14.09375)
> times_cloned = 14

> enemy_units * times_cloned
> 10 * 14
> 140

So to answer your question, the unit-groups that form from pollution should roughly cap out at the unit-group size setting; whereas the proactive attack-groups should max out at about 140 units on Vanilla+ at max evolution factor.

Edit: formatting

Thank you.