I pretty much do the same thing. I share to people that I know aren't packing every slayer in the deck so they can do little bitty pokes before I open it up to the heavy hitters to wipe her out in 30 seconds or less. You can pick the people you share. You only get to pick 20 people (whether you use 'batch select' or not, and you're allowed share multiple times until you hit your limit of 20 people.