For me it is unclear, how many HQs of each type we should have in order to apply the stratagem.
For example, if my warlord is an Archon and I have just one Wych cult detachment, can I still use Alliance of agony to gain the warlord trait just for the Succubus?
The text is following: "Choose up to one HAEMONCULUS and up to one SUCCUBUS from your army."
But "up to one" means no more that 1, so 0 is included in this range, right?
Otherwise why they did't write something like: "Choose one HAEMONCULUS and one SUCCUBUS"?