I would say it's a really bad idea to work with 8 juniors. Most juniors have a lot of wrong ideas about how to build applications, and if there's no senior around to weed out the bad ideas, you will likely not learn them on your own.
Worse still, some of the juniors can be really enthusiastic about their bad ideas and try to spread them around, so now you could have two problems: the bad ideas your originally had, and the bad ideas you learned from your colleagues.