And it gives an extra level of power and control to a campaign manager.
Each merit source gets additional power, I guess the administrators should evaluate who will not abuse it. For example, Ratimov was not a manager, but certain manipulations with his distribution of merits were recognized. The matter is quite individual, and it can't be generalized.
One more example, LoyceV managed the campaign a long time ago, and as far as I know he is still open to such offers. Do you doubt that he would abuse his merit source status by running a campaign?
A} he or she can pick and choose anyone he wants to be in the campaign = true.
B} he or she can get rid of anyone he wants to get rid of = true.
C} he can ask the person to be sure to post in certain sections for credit = true.
D} with source merits he can boost a person to earn more = not true for icopress as I think is is not a source.
To repeat, merit source status certainly gives a certain power here on the forum. But the example of the conflict you mention is probably not the best.
If the manager himself decides who to accept in the campaign, why would he force anyone by giving him an unrealistic number of merits? He can accept them even if he earns only one merit in 120 days.
Campaign managers today generally have their hands free over management. So, for example, they can always make a custom deal with a user, regardless of their (rank) merit count. there is no need to build someone's rank, it is enough just to accept him in a higher-tier position in the campaign.
I don't think any intelligent manager would risk his reputation for merit abuse. As far as I know, most of their clients come from outside the forum and don't know much about things like merit, sources etc... Certainly, the label "abuser" reduces the chances of someone being hired.