I agree with Todd, there isn't a "perfect balance" per se. It's all practice and it'll all help you become a better player. There is no substitute for drilling your hands and feet and working on technicality.......but making music with others is one of the best ways to learn musicality IMHO. Remember, just because you can, doesn't always mean you should. Playing with others is a great way to learning to know the difference.So yeah i guess the moral of the story is it wont, but you need to have the perfect balance of practice and jamming? And the more you know the more you can play?
For the most part, the ability to listen to other players and interact tastefully and appropriately is what will get you hired.....not how many singles you can play in a minute.
Do 'em both.....as often as you can.