It's called building up a precedent. It's like when a patent troll goes after a bunch of small fish (possibly setting favorable legal precedent along the way), then tries to use that momentum to go after a big fish, using the failure of all the small fish to adequately defend themselves as 'proof' that the big fish are should just give them a bunch of money.

If you go after the big fish first, then a large, competent legal team may just blow you out of the water. Not only that, they may set a legal precedent (that is damaging to you) in the process.