Ran some trials with my older NH castoffs and the 7 and 8 year olds hacked up in all my flat trials!!!. Looks like my flat stable is going to be full of older horses. My best 2m4 horse is a 8yo 3 mile hurdler now

Funny you should say that, in my flat game I tend not to trial anything beyond 5, usually 4. However I bought an 8yo 1m horse an trialled it, an he destroyed everything, this was about 15 seasons ago, and he is still in my trials now, even occasionally pops up with a win now an then. I also bought an 8yo that was one of my cast off's around the same time, that also easily won my trials at the time. I put it down to the new patch at the time, as it was the one where we suddenly started get 100 potential too.

I've only just started my combined today, so it will be easier for me to do now

Combined is definitely the way to go. A lot of my Nh horses have benefited from integrating with flat lines and vica versa. The only thing that stopped me playing a combined game in other SO versions was the stable size. But with 500 horses you can easily breed enough horses to run a flat and NH stable in the same game

I love the NH in real life, by far my favourite over flat, however this will be my first attempt with NH over the many years I've played this game, should be interesting