Let's talk about trainers first. Trainers themselves are a source of information. Their presence enables young people to learn something from them.
Around the world, we have seen that the attendance rate of immigrants goes up when people from other ethnocultural backgrounds are involved in trades. I feel this is one possible solution.
As to rural areas, I am not able to give you any exact numbers. However, I do know that the retention rate is very low, as you pointed out. The problem stems from the fact that, at the outset, when we started to regionalize immigration, we did not think to establish a link between the economic profiles of the regions, meaning the real needs of employers, and the profiles of the immigrants being recruited.
CAMO-PI is proposing to promote micromanagement instead. That means knowing the real needs and recruiting the appropriate people. The trend you have noticed is also a result of the so-called family class immigrants. Individuals recruited as part of efforts to bring families together have not been assessed and, sometimes, they do not have the necessary skills to meet the needs of a specific region. That is why there are gaps. In any event, it is important to know that we just have to deal with that.