The Philippine military is corrupt, just like the rest of the country. Will they fight?
There is corrupt and there is corrupt. But that does not necessarily mean that fighting spirit is low. South Korea in its time was vastly more corrupt, what we know today as the Chaebol are simply institutionalized corruption from long ago.
The Filipinos absolutely will fight. The armed forces are professional and the troops are notably self-sacrificing, as seen in the siege of Marawi - Falluja x 5. The macho is strong there.