Well, dairy-bred beef cross calves are likely to be more tame than weaned sucklers. The former will have been reared on bottles or buckets of milk, taught to eat cake and straw, and should be well-handled. The latter will have run outside with their mothers and will have had minimal human interaction.
Some dairy farms rear some of their own beef cross calves to weaning and then sell them in the weaned calf or store ring. Others sell them at a few weeks old to other producers, some of whom may sell some of these animals on at ages from 6-12 months.
If you can, go and watch the trade at your local mart a few times. In Carlisle the two sales are called 'Weaned calves' and 'Store cattle'. It's not a totally clear distinction - some weaned suckler calves may be sold in 'Weaned calves', and some dairy-bred bucket-reared animals may be sold in the store ring. You can sometimes tell a lot about how tame, or otherwise, they are, from how the seller behaves in the ring with them
Talk to the sellers before the sale as they settle their beasts in the pens, talk to the auctioneers about what you are looking for - they will be able to tell you which producers sell the kind of animal you are seeking.