From a third person perspective, Queen Mab believed that the summoning of the Orc Army was all due to Shiva's powers. She never expected that it was the third party 'magician' who she had detected previously within the vicinity.
That was also one of the few reasons why she used her wide area spell, Ice Age, to remove any possible hindrances or assistances against Maeve's opponents. However, the rest of Jin's minions saw it as a way of her flaunting her powers.
Still, Jin was relieved that the operation ended minutes before she decided to do that. (Else, the System would have been very unhappy wasting resources trying to resurrect his minions and at the loss of the Animal People.) But perhaps, it could possibly be preordained that Jin's monsters had to fight against Queen Mab despite it being just a mere distraction. (Or he just had terrible luck.)
