You know, there's a few ways to counter plunderers. The simplest being support. You could also run later during the day/event, or during events such as great ninja war if you're in an inactive group. Sure, some people have alternate accounts, and that's not really fair, but there's not many people, and removing plundering coupons would also ruin the aspect of convoy, in my opinion. You'll just run a convoy without any risk? It's made to be risk and reward. Not just a free reward. Removing the coupon plundering would cause nobody to plunder, since it's either 35 coupons or a lot of coins. Seriously, who'd pick the coins? I personally don't even run S or A unless I want to get in the daily.

And besides, you could pay like, $100 to get 5k ingots faster then you can make in a month, and you can get various other things to get even more stuff. P2W, this is mainly a P2W game, so....

Plus, only a certain amount of people can plunder, some of the strongest don't even choose to. I don't plunder (much) nowadays, and for some of us other people, it's one of the few ways we can keep up.

Edit:Also, regarding ingot plunders, why do you want this game to be even more p2w?