As you can see, there isn't much interest in your campaign. You have of course the right to make your own rules and conditions as you see fit. But you might want to consider why there is very little interest, and try to make some changes. Change your approach from quantity to quality. That could attract some more users.
I wouldn't call it Stake's fault. So many campaigns started since the price surge in October that the supply of available participants has gone down. That's why most of the campaigns are filling slots slower than before.
Currently there are only 9 Legendary users applying for the campaign and that is much less than other campaign as only Legendary rank is required. If the manager can consider Hero member for apply, perhaps more application will be seen and considered. But since the OP has the right to determine the rule and payment structure, I think we can only suggest the best. Good luck with that, managers.
Does it really make a difference? It took Wolf.bet 3 weeks to fill all its Hero member slots and they're one of the highest paying campaigns right now. (they just now ended though)