You can put boars and wolves in the same pen where they can defend one another. Better than a pen, though, is to use your dry moat. Make it a bit wider than necessary and fill it with boars and wolves. This happens very fast. You can grow food for the boars in the same enclosure and when it is ripe just pull it out of the ground.

Then you'll want more wolves patrolling the outside as well as the interior compound.

And leaving the obvious for last, when an event starts hie thee to thy animal pens to help with the defense.

Finally, rotate your tires. hth.