That merchant is suspicious.
Even at the start, him being there, asking for support willy-nilly, not even discerning who he is recruiting first, not even going through the Guild first to have a better understanding of the guard's background he is hiring.
Then here is the MC, actually has a princess in his care, not even double nor triple checking the merchant's background. He is too carefree. Seletia is more unprotected than the MC thinks.
Page 15: Neya is so adorable 🥰
Tailing her supposed to be master.
Technically, Neya vowed to serve the MC only, along with the other 7 swordswomen under her. So, her actions are actually normal.