You could merge in the order you wish to be executed. With each button press of the macro it will execute one action from the list, so for example you press once you activate convalescence, then second time you activate sentinel and so on.
You could also merge few others like Circle of scorn with total eclipse, that way the first one will be circle of scorn and then after next button press eclipse will go.
You could also merge spirits withing with any GCD ability you want, or requiescat with holy spirit.
I have them, its easy.
My deffensive cd macro is this :
You could edit it if you want, from top to down each button press will activate one CD after another./macroicon "sentinel"
/ac "sentinel"
/ac "rampart"
/ac "bulwark"
/ac "convalescence"
/ac "anticipation"
You could put sentinel after rampart or convalescence, whatever you like.
The other one spirit withing i have with fast blade
So using fast blade will activate the CD skill first, but i have to press it again to do fast blade, you could put any GCD in the place of fast blade you want./macroicon "spirits within"
/ac "spirits within"
/ac "fast blade"
As for AOE abilities, it looks for me like that
You press once you activate CoS, pressing again will use eclipse until CoS will be up./macroicon "circle of scorn"
/ac "circle of scorn"
/ac "total eclipse"
Same you could do with requiescat and holy spirit (i dont use it personally, but maybe i will set it up later)
With those macro you save about 6 buttons./macroicon "requiescat"
/ac "requiescat"
/ac "holy spirit"
/macroicon ""
Is a command that will show you the skill you want to be shown on the macro button.
This is how it looks like for me, i have no problem with button bloat at all and i am playing on ps4 pad.
I just set up the separate action bar for CD's just for the sake of knowing their cooldowns.