When to assign Narrowband tracker?

[Janus]

Hi this is a noob question (well I am a noob ) but I get the impression that there are some disadvantages in using trackers in narrowband passive sonar.

I am usually playing the 688i platform. Question: Should I mark contacts in narrowband (most of the time towed array contacts) if I cannot get a tracker in broadband or should I wait until the contact is visible in broadband before I mark anything in narrowband?
Which frequency should be marked in narrowband, the strongest ones (which are shared by many platforms) or rather faint ones (which makes the difference between platforms)?

Do you get what I mean?

Oh and do you mark both contacts (true and ambigous) on the towed array before you make a turn to resolve the contacts and delete the ambigous contact afterwards, or do you make turn first to find out which contact is the true one and then mark it?

Thanks in advance to everybody who will help me out on this...