Leaning the mixture

The school that I’m working for at the moment is extremely adamant about leaning the mixture and I wanted to know if these procedures are normal to you guys. The only time that the mixture is allowed to be rich is takeoff, final approach, and maneuvers. The instructions are to lean the mixture at 700ft AGL until there is a slight drop in rpm. I just find this to be a bit strange because I was always trained to keep the mixture rich until 3000ft. Not only that but we are told to do full power climbs with mixture lean and descents as well. Even in the pattern we don’t go mixture rich in the downwind in the pre landing check, it’s only once we are lined up with the runway. No only do I find this odd for myself but I have a hard time accepting that i have to tell my students to do this. I feel like having a new student leaning the mixture so low on takeoff and constantly lean/enriching the mixture in the pattern/maneuvers opens the door to some problems. I am a new CFI so if I’m overreacting please let me know. Also this airport is not remotely close to a high density field. That’s pretty much a non issue here.