I think it would be interesting if Jack and Joe separate but I have mixed feelings about this.
Advantage: Jack and Joe are different personalities. Jack (gay, camper, fatter, bad skin, shaved head) is bitchier than Joe (straight, more assertive, slimmer, normal hair, argued with Daniel).
If they went their separate ways as HMs they would interact with others more.
Plus we would see less of their rehearsed, tedious 'comedy' skits
Disadvantage: It would be harder to evict them as soloists (unless in a twist of luck they went in a double eviction). Also Hms who prefer one over the over may be unwilling to nominate one as they wouldn't want to be seen to overtly favour one over the other.
What do you think?