No. That's not normal. Unless you are closing out on a corner shot or something like that.
Too many defensive schemes can be a problem all by itself. It comes down to practice time allowed and how much time you can afford to spend on defense, in the allotted amount of time. Do you really have enough time to teach/learn 3 different defenses? Is it impossible to learn them well enough to be good at them? I've never been a fan of defensive scheme switches during games. I'm going to play 1 defense and I'm going to make sure my players know it like the back of their hand. I might tweak my base defense. Run some junk late in games, to confuse the other team and break a run. KISS. And in today's game, everyone shoots the 3 pt shot. So, I have never been a fan of zone defense and I'm less of a fan today, than I was 30 years ago.