Many people switch out Sharla because her damage contribution is so much lower than other characters. She gets the job done, sure, but it can take a while.
For your earlier reconstruction question, this page of the Xenoblade googledocs has all the things necessary and where you can get them. There are some location and NPC name spoilers in there, but only very minor. Nothing in my scan looked like a major spoiler, but look at your own peril.
awesome. thanks!