[artdutra04]

So you're running two CIMple boxes and two Toughboxes?

This is a problem screaming for a hardware fix.

The negative side effects can be mitigated in software, but you'll likely have to use encoders and velocity-PD controllers for each of the four wheels to maintain consistent output velocities. While I am not familiar with the supplied Java mecanum drive framework, it may be necessary to write your own mecanum drive code to achieve these objectives.

The best solution is to call up other local FRC teams and see if you can trade either the CIMple or Toughbox gearboxes to have four identical gearboxes. Most FRC teams are more than willing to trade (equal valued) spare parts to help other local teams.