If I were Manly, I would leave the backline as is. There are no weaknesses worth investing money in. We've also got two elite halves...I'd be looking at David Klemmer as the only player to bring in from outside.
The biggest weakness we have is in the prop rotation. They are doing enough to keep up at the moment but in big games, I think we could get rolled. Aloiai obviously helps a little but if we could have Klemmer and Paseka start with Taupau and Aloiai off the bench, it looks better than bring Sipley, Keppie, De Luis and co into the game.
Sipley and Keppie are genuine bench players and nothing more at this stage IMO. Paseka and Taupau can have off nights where they go missing. Klemmer is always consistent and super competitive. We probably don't have the coin unless we move someone on so I doubt it'll happen but even if we have to lose Taupau, I think Klemmer is a yonger and more consistent prop anyway.