Prelim 1 is one of the scales of training test so more of the marks are dependent on the collectives. Prelim 13 has plenty of canter in it. Both are fairly straightforward ones though.
I'm not a big fan of 1 as it's quite fiddley (1/2 10m circle onto the centre line and a figure of 8 and a free walk that is a zig zag across the school), 13 is OK though.one thing to bear in mind it 1 has 9 movements to 13s 15 so if he isn'tv. fit then 1 may be a better one to do??