tough. which is why under lafate's guides, he mentioned it would be best if your starting PS summons included a princess. under most circumstances, a valk would replace a princess (simply takes way longer to kill the enemy unit). Unless that unit has to be killed within a time limit (before next wave spawns), otherwise just a valk will do. most of the time you won't get the free slot to place a mage/witch for that magic dmg assist