DislikedYou should just treat them independently IMHO,
Because look at it like this, you're short Eur/Gbp and long Eur/Cad but that doesn't always mean that you're looking at a weak euro in one pair and stronger euro in the other, the price movement may well be caused by the other pairs...i.e gbp and cad...
Ghous.Ignored
As some have written it before me, you are simply ordering three currencies against each other, instead of the normal two when you take a trade:
Strongest: GBP>EUR>CAD: Weakest. So you expect EUR to be stronger than CAD but weaker than GBP... Does that make sense?
Josh