I think the number of post is not a problem but I like the suggestion to lower the minimum so people will not be force to post just to hit the quota.
I still don't know why these people are keep complaining about the rules for bounty, If you know you can't keep the work on your job why did you apply then? As far as I know bounty managers are not responsible on the campaign rules, they are just based on forum rules which abide the the rules of bitcointalk. They are on staking, checking and reporting.
Let's get real here, we know there's a lot of bounty hunters that are just posting non sense just to pass the requirement weekly so they can get a stake, so I think the process should start in the selection process, bounty managers should give time to to do a manual selection process.
Having that said, manual selection process will take a lot of time to do since there are approximately a hundreds of bounty hunter in a single campaign, even a thousand if it is known and big campaign.
What could be an effective solution is that general ruling for campaign should be, participants must scatter their post on different sections making the signatures appear on every sections. It is an eye sore seeing the same poster just right after the thread you've read into talking about nonsense matter.