What minefield? They can have enforceable non-competes for at least the next 4 years. After that, maybe not, but it's so easy to include a non-compete clause into a new employee's paperwork that there's no reason not to do it, for companies that suck (that is, more or less all of them).

Even if they don't intend to go through the trouble to enforce them, they have a chilling effect.