New managers should not have level 5 trainers to start with. There's no gain in that as you often la k the material to train and the knowledge how to in order to get the most out of that trainee. An advanced trainer will also get the job done just as well for new reams at a lot lower price.
I think that slightly increasing the numbers of the higher levels would be the way to go. Not by a lot, but still enough to make sure more people can get a hold of them. Top trainers should still be expensive imo. And in a way they help to take money away from the market.