That is why I suggested some larger girls if they have extra. I think they have several breeding pens set up so finding spare pullets could be tough. Realistically though since they are finally getting fertile eggs they could hatch a few soon and hope for some pullets. In the meantime go through your breeding pens and pick a lady or two, they do not have to be bantams to house with him. This will teach him manners with hens and if you can hatch some pullets swap them out in about 4 to 5 months.How many hens are in the 'small bantam flock"? And, how old is he compare to the members of the other flock? I'm inclined to say get him a couple of pullets of his own....but it really depends on your answer above - and whether the other flock has seen him (i.e. somewhat familiar if not integrated) Also - general flock dynamics.