With deciduous trees, you have options on how to develop movement and taper.
1- depending on its size, The trunk can be bent with wire. Sacrifice branches can be used for taper.
2- pruning the trunk - IMO, pruning produces the best taper and movement in deciduous trees. Of course wire will be used as needed to move the new leader in the right direction. There are generally two approaches to pruning for taper and movement.
2a - grow the trunk to desired thickness and prune to grow new leader. This is repeated for each new section of trunk. This is a quicker path to the desired thickness, but will leave you with larger scars that take longer to heal.
2b- cut and grow. In this method, you grow the tree and then cut it back every year or so. This is a slower process to the desired thickness than 2a, but leaves smaller scars that heal quicker. Some will argue this method also gives more natural movement and taper.
What you should do with the nursery stock depends on the nursery stock (pics??). Short answer is that if the base of the trunk has the desired thickness but the trunk lacks the movement and taper you want, you will need to chop it back and grow the new leader.
Note - this doesn’t address nebari (root flare) which is essential to the trunk.