Batch painting is an important aspect of my painting method. With no permanent hobby space I can’t just leave things sitting between painting sessions, mix in work, a two year old and other family commitments and I’m lucky to get in an hours worth of painting in on a week night.
With uniformed armies it’s easy to batch paint. Build a dozen guys, prime with an Army Painter colored primer, slap them into GW painting handles so I don’t fat finger the paint off while manhandling them and go at it. I’ll add a tiny bit of uniqueness to the models: mixed equipment, different colored boots, different tufts on the bases. But for the most part I’m just going down the line and painting the same parts the same colors. When I’m painting a hundred infantry and weapons crew this is the only way I can get a force done in a reasonable time.