Railways can at the most ask them to go the gen coach where there is not an inch of space. And even if they do go, the moment train gets into another state, they come back to sleeper coaches. With only 2 gen coaches, it is simply insufficient for gen passengers.
The only solution is to have a daily train as against the current 3 trains running from kerala to GHY. It is not that advisable to travel in sleeper at least for the end to end journey in this sector.