I think that is how most powerlifters train, between 1-3 or 1-5 reps.

I've read how some of these powerlifters train and the workload is a lot less than how bodybuilders train, of course their lifting some heavy ass weights but the overall volume is very low.

I actually tried training like a powerlifter for a while. I didn't like it. I felt like I wasn't doing anything, yeah I got stronger but I missed the feeling of having a pump, and my shoulder started bothering me. Putting that damn bench shirt on is a workout by itself. I bagged my little powerlifting routine after one month.

Slash I think your teacher was right if getting stronger was the only objective.