Fixing Aldi apple trees

I think in the first year, I'd just lightly trim the leader and let them get on with it, as the more leaf they have the stronger they will get and should get their roots established. Then next winter you can decide if it's worth training what you've got, or give them a heavy prune to start again.

I should have added I've put them in large pots / planters as I've not built the wall to train them against yet    I was planning to create a cane framework for the time being.  I have no problem cutting them back brutally, I'd rather get good strong growth than making do just to get fruit quicker. I'll have to take another look at the trees, am I going to see the difference between a "fat" bud and a thin one ?

There's room at the top of the garden for a number of standard shape and size trees, but it's going to take me a few more years to have that area ready.