et al.;
There's another way to look at this issue:
Palm Beach County has been using this butterfly ballot layout for quite some time (don't recall exactly how long, many elections stretched over several years, at least; I've been here since '85).
Anyone who has voted in recent Palm Beach County elections should have the practical experience they need to utilize this ballot format without problem (Palm Beach County has a population of ~one Million. For the sake of this argument, I'm assuming that at least 40% are eligible to vote: 400,000 people.)
If 19,000 out of 400,000 people can't figure out how to use the ballot, they could be incompetent, or they could be new to the area and are inexperienced with the ballot, or they have been here for awhile and they haven't been voting in previous elections.
If they haven't voted in previous elections which used this same ballot format, then they have voluntarily robbed themselves of experience using these ballots in smaller, less critical elections where making a voting blunder is of considerably less consequence.