Frankly, I can't agree. I happen to love playing as an Antagonist, specifically because it allows me to be a sneaky bastard.  I feel like the problem you're facing is more of a moral one than a problem with the game itself. Since you're at a disadvtange as far as intelligent assisticance, you need to use cheap tactics as an Antagonist. It makes how the mode works. You need to capitalize on when the Raiders turn their backs and swoop in to finish them off when the AI soldiers overwhelm them. If the Raiders clump up, they can't complete their objective effectively, so use that to your advantage to buy you time to pick them off. Wait around corners to grapple them, snipe them from a tiny lip in the sky, grapple them while they're busy killing the AI. It's intended for you to be the sneakiest of bastards. You are playing the bad guy, after all.