I'm playing FFII at the minute and I'm right at the end and Leon has just joined my party. Now, I don't mind the fact that he joined so late, I do mind the fact that he joined with about 1000HP and 5MP when the rest of my team are rocking 9999/999 stats. I've had to spend a decent amount of time just levelling him up so he's not fodder in the final dungeon.

I honestly don't mind either approach as long as it's done well. Just make sure if you're introducing characters late, they are suitably levelled for the job dammit. I don't want to experience the equivalent of wheeling in a paraplegic in a wheelchair as my fourth party member.