Hello mate, here's some improvements to the code, should be ok to raise it to final fixes and just skip the redundant parts

-- Returns true if autoplace force = "enemy"
local function is_enemy(enemy)
    if enemy.autoplace.force == "enemy" then return true end
end

-- Returns true if turret name contains the word "-worm-"
local function is_worm(turret)
    if string.find(turret.name, "-worm-", 1, true) then return true end
end

for _, spawner in pairs(data.raw["unit-spawner"]) do
    if spawner.autoplace and is_enemy(spawner) then
        spawner.autoplace.order = "b[enemy]-a[spawner]"  -- [This is redundant as trees are already marked to Z (see below)]
    end
end

for _, turret in pairs(data.raw.turret) do
    if turret.autoplace and is_worm(turret) and is_enemy(turret) then
        turret.autoplace.order = "b[enemy]-b[worm]"  -- [This is redundant as trees are already marked to Z (see below)]
    end
end

for _, tree in pairs(data.raw.tree) do
    if tree.autoplace then
        tree.autoplace.order = "z[tree]-b[forest]" -- [same order as "Alien Biomes"]
    end
end

Hey.
It's really nice you improved this mod.
Your code has been put to 0.2.2 release.

You're welcome mate!
Keep in mind that keeping the two redundant blocks (and relative functions) will only set spawners and worms at "b[enemy]...".
Trees being set at "z[tree]..." are below both worms and spawners anyways, as vanilla order is "a[tree]..." & "b[enemy]...", you could basically just pick the last four rows to be good to go

ok, thanks ;)