Well, after reading the Steering on 16F887 I think it is not possible to have 4 different PWM signals at the same time on a chip that lacks more channels.

The 887 has 2 channels, so 2 different PWM signals can be produced by hardware. I really do not have fully understood what steering is there for but I am sure not for more free channels.

The datasheet says that the SAME PWM signal can be simultaneously available on multiple pins. Not different PWM signals.

I hope I am wrong but that is what data sheet says as I understand it.

Ioannis