Hard to say, i experience your problem too. The idea, imho, is that they appear after a while so that if you look at them while you are in konoha you have the time to go in the base before somebody else steals it from you. Is to give a fair try if you aren't ready in the base.

There's a way to come to term with plunders if your server is relatively low populated and is to run only s convoys until they cease to plunder.

Personally speaking i would set plunderings in a way that if the plunderer have more power than, the strongest person in your group then you are supported by group snake and he doesn't recover hp after the fight if he wins.