CHOOSE YOUR MOUNTS To apply this you need to go into the unit's profile in adventure mode, fort mode is just highlight and enter. first pick is Rider, the second is mount, this code is a modify version of Hugelueman's marry revise code... also warmists.

Mount.lua

function Mount (rider,horse)
  --for k,horse in pairs(unit_list) do
	--if unit_rider.pos.x==horse.pos.x and unit_rider.pos.y==horse.pos.y
	--and unit_rider.pos.z==horse.pos.z then --check if they are on the same tile
	horse.general_refs:insert("#",{new=df.general_ref_unit_riderst,unit_id=rider.id})
	rider.relations.rider_mount_id=horse.id
	rider.flags1.rider=true
	horse.flags1.ridden=true
	require("utils").insert_sorted(df.global.world.units.other.ANY_RIDER,rider,"id")
	return
end 

unit_1 = dfhack.gui.getSelectedUnit()
if unit_1 == nil then
	print ("You must place the cursor over the first target.")
	return
end

print("Target the Mount and press enter")
test = dfhack.lineedit("")

unit_2 = dfhack.gui.getSelectedUnit()
if unit_2 == nil then
	print ("You must place the cursor over the second target.")
	return
end


dfhack.with_suspend(Mount, unit_1, unit_2)