I feel inclined to try and use the same parameters on each pair. I have retested my system with sliders to change the parameters instead of optimising them and tested the portfolio.

I can't get a sharpe ratio or ulcer index that I like but it shows a return of 250% a year. Realistically I don't think that it will return that much but I just have a feeling that the parameters used and the system itself will be more robust. Even if it doesn't make 250% I think it has a good chance of making between 20 and 100% which is a return I would be very happy with.