If campaigns took merit into account when deciding on the stake ratios per rank, then that could go a long way to reducing spam. I’m talking specifically of earned merit whilst being on the campaign (not airdropped merit nor even already earned merit prior to participating in the campaign, although the latter could also be taken into account).
For example:
Previous earned merit earned merit during campaign
(0) [1..20) [20..100) [100++]
Legendary: 0 Stakes 2 stakes 3 stakes 4 stakes 0,2 stake/merit
Hero: 0 Stakes 2 stakes 3 stakes 4 stakes 0,2 stake/merit
Sr. Member: 0 Stakes 2 stakes 3 stakes 4 stakes 0,2 stake/merit
Member: 0 Stakes 1 stake 2 stakes 3 stakes 0,2 stake/merit
Jr. Member: 0 Stakes 1 stake 2 stakes 3 stakes 0,2 stake/merit
<...>
The initial airdrop was a one time thing that took place upon Merit System kick-off. Those that qualified at the time (based on their rank) got it.