Not to be obtuse here, but, isn't this how 4e worked? Few, if any nova abilities - dailies were hardly encounter ending and you never got many of them. Wasn't this the source of the criticism of the combat grind? That you couldn't end encounters really quickly and instead had to go 5-8 rounds for each encounter?
Sure, 4e characters had dailies. But, their dailies were nothing like what you get in 3e or 5e. Far, far less powerful and encounter ending. So, the party had to work together to synergize attacks in order to end encounters faster.
Tweak the 4e math to end encounters in, say, 3-5 rounds and you're pretty much achieving everything
@Zardnaar wants. Simple mechanics, basic math, few or no encounter ending dailies and making it rather pointless to nova.