Sisko. Kira is out of control in the first few episodes.
If your first officer is seriously contemplating betraying Starfleet to join an anti-Federation terrorist group, and you kinda know about it, and continue to leave her in command of all your personnel and equipment, you might be a lenient captain.
^ I don't see it as that at all. Sisko even says to Kira in "Past Prologue" "Go over my head again and I'll have yours on a platter
Yes, he dealt with her insubordination, which is a separate problem. What concerns me more is the problem of her lack of loyalty to both her own government and to Starfleet, combined with experience that makes her capable of actually doing something about it.
He tries to talk to her about it, but he doesn't change her mind. Odo is the one who eventually gives her a push toward making the right decision.