Merit sources are focusing with those accounts or even those top merit rankers in the forum. Merit distribution isn't really that fair and I'm assuming that they are building their own sockpuppets to solo out and milk out signature campaigns that requires accounts that have lots of merit counts.
Merit sources are chosen after an application where they have to meet some criteria.
1. Be a somewhat established member.
2. Collect TEN posts written in the last couple of months by other people that have not received nearly enough merit for how good they are, and post quotes for them all in a new Meta thread. The point of this is to demonstrate your ability to give out merit usefully.
3. We will take a look at your history and maybe make you a source.
The application is not a formality and I know plenty of good forum contributors which applied for this position without receiving it. So those which are merit sources have to do a really good job in order to be elected.
Furthermore, merit spending is not moderated. Each user may send his merits to whoever he wants and in whatever amount he wants (being limited by the 50 merits / month to a unique user limit and by the limit of the amount of his sMerits). So far I only witnessed
one case where a merit source was accused of abusing his powers and that user was demoted from merit source position. So actions are taken in case of abuses.
OP, if you can point the finger to someone directly, do it so and bring proof for your statement.
Other than that, since it was only one case of a merit source demoted for abusing his power, I am certain that merit sources are doing their job just fine. (There were other cases of demoted merit sources, but not for abuses. This happened when the user became inactive or did not use the sMerits received for being a merit source.)