Rule number one of joining a campaign.
Follow the manager rules and dont play smart.
No hard feelngs mate but i think you should be mature enough to make your own decision not by following others. Are you sayng if they did something against the forum rules you'll either.
Also, there is no rule "don't post your earned merit count".

I don't see anything wrong if member mention number of earned merits in application post. It will be easier for the manager to pay attention, why not? especially where it is not obvious number of earned merits.
as far as I noticed BestChange manager trying to select the best participants, they will check the post history of applicants for sure, a number of earned merits can help in his selection. Though this is BestChange-manager's first campaign which they manage and he does his job very well.