They lucked out getting Michael Piller in. He replaced Maurice Hurley, who'd been doing the job for most of seasons one and two. Piller brought a different sensibility to the series to what Hurley had been doing, although Hurley still contributed a script or two during Piller's first run.
Kind of funny how fast Piller got the job.
"Hey, we really liked your 'Evolution' Script! Want to be the head of the writing staff?"