I find when females spray the males it's to let him know she is boss.
I take this as a better sign than if they just attacked each other.
What I mean is I have found that this behavior is a normal ritual with some new pairings. It's the fighting I worry about.
Now tell me if I'm totally off base gals, I'm only going by what I see, and have no problem being told I'm not right, or out to lunch
Keep doing what your doing, cages side by side, and trying them with runs and baths together.
If there is no all out fighting, fur flying, or casing things should go pretty smoothly.
I fine the ones that can't stand the sight of each other the hardest to pair, but not impossible.
The best is when they fall in love right from the start.
Keep us posted too