Ah I see your point now and it's a good one.

However I would recommend having every ship capable of putting up as good a tank as possible - you never know when you might need it

After all you wouldn't have your followers with level 1 spells and gear while your main is tanking - far too much chance of a follower getting wiped (I know becasue I've had this happen a few times recently while I've been RAF-ing a new team to 60. So I've made sure that every 10 levels or so they get their spells and always kit up with quest rewards)