I'm pretty sure many are aware of the issue. The problem is, it's heavily implied that only one of your units can be chosen by you. The other two will supposedly be randomized from your Friend's List as well as Faction. If this really is the case, then in order to take advantage of the voting bonus with certainty, the only Hero you have a choice over is going to inevitably have to be the same as your faction's mascot. (Not to mention, it's kind of suggested the voting bonus won't count if the faction mascot is from your friend or the random stranger) In addition, you need at least 10 friends to maximize the friend bonus thing, so while you could technically wipe your friend's list of all but a select few, it'll deprive you of some voting points in the process. Hence it's kind of hard to control your team and bring in a counter even if that's the obvious course of action.
Of course, I could be prematurely assuming things wrong, and maybe the system is way more flexible. Still, I'm sure everyone on Team Lucina will try to bring in Hectors once it becomes clear they need him to wreck Sharena. (Team Sharena will probably bring in Roy later in response to that)