That's very true.

I prefer levelling up people as just one job, because it saves time and energy when you're making your characters. You also have more control over the stats; with mixed levelling, getting ideal stats involves resetting at every level up. With pure levels, you wait until your average clan level hits 50, run dispatch missions with the Ally Finder 2, find several "specimens", and then judge each one like a piece of meat.

Of course, it all only applies when you're power running and shooting for the best stats. If you're just playing through the game, trying to get the best stats isn't worth the effort.