The problem is, you do need a good half (whether it's a 5/8 or 1/2). You can have all the forwards in the world to get you down the field, but without a good half, you won't be converting into points. Look at the Bulldogs on the weekend - plenty of opportunity, but they don't have a good half to finish them.
Sharks got by in 2016 because they had a strong hooker, fullback, and a dominant half (Maloney) behind a forward pack that played beyond their contract value. Currently, we have an average fullback, hooker with potential that's slipping away, no halves, and a overpaid forward pack.
We can discuss third party deals, etc. for why Reynolds chose the Broncos - but their pack is much better than the Sharks'. The also have some strong outside backs, compared to the Sharks who need to play Connor Tracey on the wing.