Family tribes are bad early world, but can be good late world if you want to speed things up, and by the point that even the noobs are experienced noobs.
Early world, when it only takes 1 or 2 hits to knock members out completely and you have 100, it's very hard to manage a heap of inexperienced players, telling them everything to do, trying to managing every single one of them. In-fact, it's rarely possible, for example a tribe of 10, making a carefully timed and successful support, spike, or nuke op, easy. A tribe of 100 inexperienced (usually frankly terrible) players, different story.
It's better to wait it out and weed out the complete failures first, you're better off recruiting those that noble out those people. You can teach some people, but keyword is some, not all. Some people never learn, and will never be good players or capable of handling their own accounts, and you will have to baby-sit them through the entire world. You don't want that. The only successful family tribes are ones that are established later world, because then everyone has their own area of dominance, and you have a much higher percentage of capable players, and even if it's their first world they are usually somewhat experienced through the course of time by that stage.