Rework, streamline, and nerf abuse of Decimate/Cleave and other such basic ability pairs

The following abilities are very similar but are slightly different depending on whether 2h or DW:

-(mutated) dazing shot/needle strike -sonic wave/concentrated blast -decimate/cleave -havoc/smash

You'd think they share a cooldown, but they don't. If you know what you're doing, you can take advantage of this. Instead of throwing a wrack to fill in that gap in your rotation, use concentrated blast since it deals more damage. This is not a huge deal with 157% abilities but a 7s cd 188% is huge. Bringing a decimate switch while using a two hand essentially lets you use cleave twice as often.

Some will defend this by saying that extra effort should reward you, but there are other ways of doing this that aren't obviously broken and unintentional.

The obvious solution is to make them share a cooldown, which I support, but Jagex should go further. Instead of the having them as 2 separate abilities, requiring us to use two bars or remake our bar (especially with melee), just make it one ability that has its effects change depending on what you use. The decimate/cleave ability will be usable with both dw and 2h melee, but it won't AoE unless you're using 2h. This is clearly already possible; cleave hits different amounts of targets with halberds than with other weapons.