We think there's only one.
Im down with that too.. The church/flock in John 10 is outside of the sheep pens.. The Lord calls to them they come out toward/following his voice into "THE FLOCK".. So it seems there is only on church/flock.. Yes there is one flock.. You really cant call those in the sheep pen a flock except as a flock of the psuedo shepherds in the sheep pens.. Read the metaphor there are 'shepherds that go into the pens.. but the real shepherd is outside calling some out.. Some sheep appear to be deaf.. and cant really hear the psuedo shepherds either..
Theres many of Jesus' metaphors untouched as metaphors..
Like the metaphor of the talents.. but Im into John 10 currently.. these metaphors are deep Dawg.. DEEP..