KISS. Keep it simple, somone said!
Don't be misled or sidetracked by considerations of Vmcg. During normal operations, Vmcg will not be a factor in Take-Off calculations. I assume you are considering the situation where V1 might be at or close to Vmcg after taking into account the derate/reduction calculation. Remember, V1 will never be less than Vmcg. Should you encounter an engine failure below V1 and elect to abandon the Take-off then you will fulfill all the performance requirements.
If the engine fails at or above V1 then nothing needs to be done to the operating engine to fulfill the obstacle clearance requirements for the 1st and 2nd segment climb sectors.
If obstacle clearance becomes a factor then provided you are flying at V2 plus 15 kts you will always be safe if you then advance the thrust to Go-around power. You just need a bigger bootfull of rudder.
Forget numbers, apply logic!