The local sale barns in this area sell according to size. The lightweights go early and they work their way up in weights. Steers get sold first, then heifers. Cull cows last. That way it doesn't basically make a difference if you are there at 4 a m or 8 a m to unload. The first ones to unload light calves will get sold in the first pen of light weight calves, the ones unloaded late will get sold in the later pens of lightweights, but all the light weight ones get sold before the heavier weight ones.
We try to be there by 4 or 430 am to get in line during the fall runs, unloaded by 6 a m then can go back to get a second load if need be. I have often had to sit in line for 3 hours on busy days in the fall runs with a second load.
You will see some 4 weights get sold in amongst 5 weights, but not like 4 wts then 8 weights then 5 weights. Groups of 4-10 sell as well or better than singles or pairs, but again not a big difference if they are good ones. Lots of single, pairs and small bunches are sold here since so many are small farmers with 20 to 40 head.
They will advertise any cow sales, and if you happen to have big groups the yard will tell the buyers ahead of time. Each group, if vaccinated or weaned, will be announced as they come through the ring.
We have sold both "weaned on the truck" and weaned and fed 30-60 day calves. We do as good or better with the weaned on the truck calves. Most of ours at that stage do know what a bunk and feed are, so it's not like they just came off the back 40 with no idea of what they are doing. We don't creep, but the calves learn from the momma's that when we call there is feed, and it is good to eat, and they are in the pen as fast as the cows in most cases. Even the ones we feed out in the field, know what we are about when we holler for them. 99% of the catching up of the cattle is done by one person, calling them in and we seldom have to do more than go around a few reluctant calves to get them to feel better about getting through the gate in there with momma. There is always that one or 2 that are going to be stupid.....