I'm confused - you don't Leidner to be the starter, or you don't want Leidner to be confident. I guess I would rather have a confident QB as opposed to a QB who doubts himself - whether he is the starter or a backup.
Seriously, I think you mean you don't want Leidner going into the season thinking he has the starting QB job locked up. At least I think that's what you mean......
As far as Croft, in his admittedly limited playing time, I haven't seen anything yet that makes me say, "that guy should be the starter next season." As the risk of sounding like Yoda, wishing something was does not make it so.