They didn't know the procedure that these two would follow with Jake Long and that he might start doubting something if they took too long.
For this reason, it was really important that they break these two as soon as possible, and learned everything they needed.
But even then it wasn't completely safe because these two might activate some trap or alarm for Jake Long, and all their cover would be blown up.
That was why Tianlong Xia had left an option as a last resort to the situation. A manual on how to cast a slave seal on both of them.
She had already checked both of them herself and knew that each of these two had a seal already inside them, and also their cultivation was much higher than they showed.
That was why she had given clear instructions that if they weren't able to break them in 2 days, then they had to use the manual and turn these two into slaves.
