Your horses aren't actually trained... hence why they're coming out negative in any trial event.
For starters:
They're level 1 & 2 - highest level is 25
You CAN'T raise actuals to 200 as a novice
Seeing as you can't raise actuals to 200 - you can't event train, which will stop them from having negative trials.
This is a "fully trained" horse. All stats are to 200 & level is 25. It's called "statmaxing" or "roll prepping." From here he can be
rolled (Arabian birth cap is Eg/Eg/F/In - these are the highest stats a foal of that breed can be born with) to make him a better BREEDING prospect. These stallions won't do well in trial events either because they need to be
event trained.
This is an event trained horse. Notice how she's level 25 and some of her stats are WELL above 200? She has been trained specifically for the event she is being evented in, which in this case is Dressage. As a novice you can buy a horse who's stats are all at 200 and tweak them to be semi-eventable in a certain event (I say semi because sometimes stat maxed horses who are then tweaked for eventing don't always turn out well).