On a personal level, I can sort of imagine balancing out my functions. Maybe some sort of adverse conditions would move me to improve my Te (one of my worst functions) so as not to get walked all over in a more cut-throat environment. Meanwhile, I think my Fi would get tempered a bit as I stop having time to consider my values so much while I'm Te-ing it up. I have no clue how I could bring my Ne and Si together though. If it happened, I'm sure I'd lose a lot of my talents, but might become a little more productive. But let's say it happened, and let's assume that all my middling functions are already developed to a decent extent. I'd say I'd probably be able to function (no pun intended). I'd just have to be living a very varied life to keep all the aspects of my personality active, without the constant change ever really being noticed. It doesn't mean I'd be a great person, or a mundane person. I'd just be used to a particular balance of circumstances and trial-and-error that would be one in a billion, and hard to replicate.