Bucks tend to be loners for the majority of the hunting season (Sept-Jan) - except during the rut when they will search for estrous does and pursue the ones that they find. The mating season does not herd them up but rather a single doe entering estrous will attract pursuit by one or more bucks. When this happens, she will usually not remain with the rest of the does. Even though the bucks are not herded up with the does, they will be nearby.

It is common to see multiple does together in hunting scenarios - especially around preferred food sources. There may be other does around that you don't see when driving by. Yearling bucks are driven from these doe groups before the rut to prevent in-breeding. This partially explains the high mortality rate of wandering, young bucks.

From a buck hunting perspective, it is always wise not to shoot does around the rut - if your goal is to shoot a buck. One of the best things that you can see during the rut is a single lone doe walking briskly past your stand. Don't spook her, let her walk and be ready for the pursuing buck.

These are general statements about a complex animal. There are always exceptions.