Wow, it depends... I would load the good loader first, then the other
one... I load all the time with horses my horses don't know, but I
have a good partition between horses so I don't worry about them, is
there a good nose partition between the horses in your trailer?
If you have time you could introduce them, but it can take time, I
mean weeks of time to get horses comfortable with each other...
Raven's Grandpa always said put Vics on the nose when you introduce
horses, I have never done that before... but maybe others have used a
dab or two, lightly as to not burn the soft tissue of the nostril...