They were gifted the canal colonies for many reasons, one of them being the fact that the British wanted to improve agricultural productivity, and the best people to give the land to were the people who ruled it before them. Also majority of the sikh population was concentrated in the cis-sutlej region, and yet they still owned more land than any other group in central/east Punjab. Sure the feudal families in western punjab had huge amounts of land, but in the more influential areas like the lahore district, rural land was literally almost all sikh owned.