PHI hasn't been able to keep up with attrition over the past couple of years, much less replace half its pilot force. The company has publicly admitted that it has been hiring less than half the number it needs, and well over half the ones it has hired have quit before completing training. The only way to accelerate hiring is to hire very low-time pilots and give them minimal training; even that won't cover the shortfalls. Even with huge amounts of mandatory workover, they couldn't man all the aircraft before the strike, and they won't be able to man them for years via hiring replacements.