The Pickering (at least) will probably try to set fruit this next season. You need to give some thought to whether you let it hold any fruit yet or not. With the existing root system, you don't need to be concerned with unduly stressing it, but letting it fruit will put load stress on branches that are probably not yet up to holding the weight and somewhat delay the tree getting bigger/stronger. Trying to get ~10 fruit off of it could cost you your shot of getting 50+ fruit off of it next season.
It's not a call you have to make now, and it doesn't have to be all or nothing. Just be aware that any branch(es) you let hold fruit will miss a significant portion of the growing season. You'll probably have to prune with extra care to make sure any fruiting branches still get good light; the other branches will go through a few pushes and could shade-out the fruiting branches (further stunting their development). Heavily-shaded branches don't thrive.
