Hi,
Last year, during a project of mine, I had to use two Dual VNH5012 motor drivers simultaneously to drive 4 DC motors. Unfortunately, the default Dual VNH5012 library was not suitable for simultaneous usage of two of them. So, I modified the default library and I would like to share my version with you in case someone needs such a thing. You can reach the my repository using the below link.
Link: https://github.com/ylmzkaan/TwoPololuDualVNH5012
Thank you,