It can be experimented with premium trains and services in India and on the routes where traffic is very less. It is one of the best way to optimize and save resources. Even Highspeed Trainsets in Europe are joined and amalgamated. I remember traveling in Rail jet from Zurich to Vienna. The train starts with single train set from the Zurich and by the time we reached Vienna , we were in the formation of two train sets. The other one joined us at Innsbruck which is an Austrian city. It does not make sense to run full length train all the way from Zurich and Vienna. Then joining and unjoining two train sets are relatively very easy as compared to coaches which are required to be shunted... Indian Railways should run such trains on pilot project.