In my opinion sweeping strikes could yield some of the highest numbers possible, if you abused its mechanics back in vanilla. %-Damage modifying buffs applied on the sweeping strikes damage on top, leading to some insane numbers in some cases:
https://youtu.be/McCwTT-0Eiw?t=220https://youtu.be/qbIUYT08FyI?t=975This guy did a 6.5k sweeping strikes with alot of buffs missing and without debuffing the traget.
Technically you could do 11k sweeping strikes + (6k execute *(1.3+0.25+0.2+0.03+0.1) with berserker buff, enrage, death wish, 2h weapon specc, DMF buff.
Then you could multiply that by another 1.3 if your targets were naked warriors with recklessness and berserker buff..
Unfortunately (or luckily if you look at it from a class balance point of view) sweeping strikes never worked like this on nostalrius.