That's my one concern with Tyler's posse. Everyone is an Arcane Backgrounder, and that's going to be messy... Also, magic (in any form) tends to be a powerful security blanket when the weird stuff hits the fan. There;s some Huckster powers that can really short circuit an adventure, for example...
Of course, if the fact that the entire party is magically talented is used for the campaign, it might be interesting. This posse could get trashed if they are ever in a situation where they can't use their magic, however... Lack of characters concentrating on other skills is a definite minus. Also, if the posse ever gets the 'bad night' for dice rolling I've seeng roups get,t he show might end right there as multiple backlashes occur.