If your team doesn't have enough trust to answer this question there are bigger problems in your company.
That said, I've managed people who have mental health problems that results in high anxiety from answering these types of questions. As a manager / lead you have to know your employees and work with each of them as an individual.
If I didn't trust my lead to not potentially think less of me (consciously or not), or even worse, to use my answer against me somehow (toxic environment) ... then I definitely would answer "2 or 3" even if I was a 5.