Do these appear to be bantam chickens?

We bought these two as week old chicks and have since purchased three adult bantams. These chickens have much bigger feet (yellow and huge...not the cute lil' gray bantam feet like our others.) This rooster is about twice the size of my smallest bantam.

 

He was supposed to be a bantam. I just took a few pictures to compare him to the other bantam hens. The little buff one is the smallest.




My concern is having bantam hens with a standard rooster. He is about 3 1/2 to 4 months old. The black cochins are 20 weeks old and the little buff (whatever she is) is an adult hen.

 

so if he is a standard rooster, will that work with a flock of bantam hens or should I take him back and get a bantam rooster? I have discovered chicken mating is quite disturbing to me because it looks as though he is beating them up. My husband said, "What...do you want him to light a candle?" He just started trying to mate with the cochins that we brought home on Friday and started crowing about the same time. I just don't want him to hurt the bantams. The other problem is that my daughters raised him and love him dearly. They are so afraid that he is going to have to go. Is it possible to keep him or would that be bad for the flock?

 

We took our boy back to the farm today, along with the other standard hen that was supposed to be a bantam. There were tears, but when the girls saw him walk right into the crowd of hens his same size, they finally understood why this was best for him and our little bantam hens. Now, they are talking about a bantam rooster to watch over our little bantam hens. We will have to be on the lookout for a gentle bantam rooster....any suggestions?