That is just one scheme, a naive one. What is more likely (among other things) is that they have managed to get one or several of their colleagues promoted to merit sources which now support the farming. Do you not read stories of organized scam centers in third world countries? That is how it works. They have groups and do this together. Even if all the accounts involved are not yours it is still abuse. Further, you can make it seem more legitimate by having a strict rule of not giving merit to your own accounts across the group. In that case they would only give merit to the accounts of their conspirators and never to their own account.