I'd argue that the ratio of the time in Fighter to Attack modes is somewhat irrelevant to players who game the system. It's not about spending as little time as possible flying fighters, but rather only flying fighters when rewards are high and risks are low. If players find themselves in lots of high reward/low risk situations, they'll score more sorties as Fighter. Conversely, if they engage in a lot of high risk/low reward situations, they'll score more as Attack. Someone engaged in base defense, for example, would probably score that sortie as Attack given the high risk of dying to higher, faster, and more numerous enemies.
Of these top 10/top 100 players, how do their K/D ratios compare against fighters in Attack versus Fighter modes? How about K/T? I suspect these stats are a bit more telling.