Showing national level horses?

So I have a pretty good strategy for showing my regional level horses and below, but I'm currently running into the issue of having heaps of national level 1 horses.

Currently, I've been showing the ones who have 1250 stats and above or even 1200 and above, and schooling the ones that are 1100-1199...but that's really slow stats progression for them!

What do you guys do?

Here is the total stats that go to the show levels:
Na1 1,100-1,299 [1,200+]
Na2 1,300-1,499 [1,400+]
Na3 1500-1699 [1,600+]
Na4 1700-1899 [1,800+]
Na5 1900-2099 [2,000+]

The stat range that I bolded for each show level is the range of stats my horses must be in for me to actually show them. If I show them with stats below the bolded number, then they tend not to do all that well in showing.

Thank you :]