That’s not actually a consequence of what you suggest. It is what you wish to be the consequence.
Take 10 corporations with 10 players and each declaring one war.
Then taken one corporation with 100 players and declaring 10 wars.
In sum is it the same amount of wars and the same amount of players who want war. So when you limit the number then you force the most successful war-faring corporations to fall apart. And that’s all it will do.
The complaints however don’t come from the war deccers, but they come from the defenders. And the defenders will always complain. Only now do they use the argument of “wardec spamming” when really they complain about one large corporation declaring wars against them. They will continue to complain and make up new reasons after you’ve limit the numbers of wardecs. Alliances such as PIRAT and Marmite will pass war requests off to contractors and we will still have plenty of wars to go around.
EVE is then a PvP game and war is at its core. To have unlimited wardecs is a gift, a blessing, for a game like EVE. You however want to declare a great feature to be a curse and solve a nonissue in a control freak way, to disallow it, to limit it, to deny it, to remove it, to take it away.
Your approach to solving issues consists of negativity. Not one of your suggestions is positive, constructive and supportive of PvP, but only detrimental to it, aimed to punish the successful players. You’re not a dumb person, but your grasp of EVE is flawed.