Instead of one Pati saw two auras that have similar power through his Chaos Inspector skill, he was confused as to why there are two auras if it was the Boss Zombie. But that only means that these two powerful Zombies are not the Boss Zombie.
'Even though I can't compare it to other Zombies, these two are stronger than Megan'
Since Pati hasn't used his Chaos Inspector skill on any strong Zombies yet like the big Bird Zombie, he can't compare just how powerful these two Zombies are. The only thing he can compare them to is Megan whom he checked before.
At the very least, these two Zombies are nearing his strength.
From that alone, he knows that Blue can't take on one of them, he's still weaker than Megan so he definitely will get obliterated by these powerful Zombies if he were to engage in a one-on-one fight.
But since these two Zombies are at the opposite end of the place, it gives them an advantage.
