I'm no fire strategist but I know several career guys who are...the one thing they all agree on...none of these wars were ever won in the air, more so as the forest canopy gets thicker and steeper. They do admit that aerial attack can buy precious time for the "infantry'' to build dozer and handline. And they are at their most effective when the smaller rotary aircraft is used out where spotfires are erupting outside the line. GSA did a study a few years back on cost/benefit ratio of air resources, conclusion, least bang for the buck. It was buried, air resource contractors lobby like any other multi million dollar government vendors. Not sayin' I wasn't happy to see air attack around here the last few years, I didn't seem to mind the cost when I could see flames from my shack, grin. CalFire strategy is direct attack whenever possible, and they need air for that strategy to work safely. The Forest Service uses the "big box" strategy, back off a ridge or two and plan for a dirt line days out, and let everything burn inside the big box. Water drops dry out within an hour or so, retardant stays gooey for a few hours but eventually dries also, so it's very wasteful to dump water inside the big box. Bare mineral earth fireline is what contains forest fires in the end.
