[eluser]xwero[/eluser]
I'm not sure what you are doing with that code snippet. Is it your idea if you call the load->helpers method all helpers will be loaded? And then search for a function that is defined?
If that is the case loading all helpers to check if a function is defined takes up resources that could be used for more useful purposes and it overshoots your goal of loading certain functions from helpers because all functions are defined.
I think you should simplify you problem instead of making it more complex. Write out what your code needs to do and find the easiest solution to code it.