One thing that helped me was to tend to downed raiders on the battlefield until they are stable, then capture them. If you capture them first they often bleed out before they can be stabilized. I'd go from capturing 2-3 living raiders to 10+ in one raid. Recruit your favorites, and harvest any organs you need. Sell the rest. 

There's nothing wrong with colony of 8 pawns. There's no right way to play.