Honestly, a lot can happen in a short amount of time, and what happened with the girls while he was away was necessary; he realized this when he checked their strength in the morning.
In fact, many things changed in that short period to the point that they were almost unrecognizable. They were at least twice as strong as before, which, for a cultivator, was an extremely significant shift.
When he asked, "What happened to you?" the answer couldn't have been shorter or more direct.
"We were useless, so we just got useful," was Samira's response. She had been feeling particularly bitter since the fight with Kryssia, where she had taken quite a beating.
In these few months, all the women had managed to reach the Grandmaster stage. Naturally, Strax checked why this had happened.
It was quite a simple determination, really... The system had been holding back the girls' cultivation update while he was conscious.