Yes, you want multiple signals compounded in the same direction which increase the correlation. Oct has a slight inverse correlation, while Nov has a slight positive correlation, but add them both together and it becomes stronger likelihood.
I'll say though that the Oct correlation has weakened in recent years, but it's still there.
The biggest conundrum with seasonal forecasting is trying to fit pattern projection onto sensible wx. Nobody who was ever given a composite of December's H5 pattern would predict an above average month on temps and virtually snowless for SNE. The small nuances in that longwave pattern are not predictable at more than a few days lead time so you'll never be able to accurately forecast that type of blocking while also adding the caveat "but it won't produce cold/snowy sensible wx for us".