Using Rig Export Converter you can exchange animation data and complex character rigs between Maya and game engines (Unity, Cry Engine, etc.).
To prepare your rig for exporting select a character’s model and click “Convert”. Rig Export Converter will generate a new skeleton for clean exporting. Now select the model with new joints and export the rig to any format.
Are your characters doing weird scale things coming from Maya? Since some game engines not support scale compensate, any joint hierarchy you use in Maya with scale compensate looks wrong. But there is no limitation for the scale compensate setting with the Rig Export Converter plug-in.