Well, seven is already a pretty large number for a main character group. When a show was made called the Chan Clan, I believe it had about twelve characters. It was harder making a scene where twelve different characters had different opinions and different ways of doing things, so most scenes used a different amount of characters. For example, during an episode, most scenes spilt the group into teams, like a set of two, three, three, and four. Any more than seven characters will make things a good deal harder on the writers, I think. Look at all the Digimon series. How many episodes had every character in the same place at the same time? Being split into small teams or going solo for a while was used during almost every episode of each of the five seasons. Even some LBT episodes had the gang split up for a majority of the main parts or didn't show them at all to make it easier to write, like:
Canyon of the Shiny Stones- Littlefoot, Petrie, and Chomper in one place during most of the episode, and the others were elsewhere.
The Mysterious Tooth Crisis- Ruby, Cera, and Spike in one place during most of the episode, and the others were elsewhere.
Days of Rising Waters- If I recall correctly, Littlefoot, Petrie, and Chomper made up the only gang appearances the whole time.
With more charcters, split ups like this will probably be much more frequent. The more characters a show has, the more complicated it is to make sure that each one has some part in it. Although sometimes, large numbers can result in characters not showing up at all, like Days of Rising Waters. We all have seen some problems with the episodes. If they have even more work to do, like including more characters that will be around the whole season, I expect to see even more errors.
Don't misunderstand me though. I would love more main characters, but if so, episodes might be about certain ones and/or certain episodes would have many parts where the gang members would be in separate places most of the episode. I had an idea for a new gang member that I already posted in the Characters You Wish They Brought Back topic, but after looking over my post there, even I saw how ridiculous of an idea that was. But now that I'm thinking a bit more realistically, if it works out, new members I'd like to see are: Ali for one, so that there can be some romantic scenes and even episodes with her and Littlefoot. Perhaps a young rainbow face sent to live with the gang for further study, but with little or no power, or not very knowledgable on how to use it, or it was sealed to avoid suspicion if he or she ever wanted to use it in public. And of course, the rule this character would have is not to reveal secrets of the world, but maybe a few times he or she blurts out of couple things for interesting reactions. (Then again, this last suggestion isn't realistic at all either, is it? Well I tried. This is more likely than my idea in the new character idea topic at least. I think it is anyway.) I like Mo, but the water would restict him too much. Any Mysterious Beyond visits would either be rare or not possible. A tinysaurus or two would make a nice edition, I believe. Although since they all have such interesting personalities, I couldn't decide between them all to pick out just one or two of them. And those are my suggestions for new gang members if that will happen. I hope that some of these could possibly work out. Later!
