Really all dl need to actively rotate in the modern cfl. You don’t gain much by sending 1/2 and playing cover 1, since teams will just chip WRs, roll, throw at the gap and with the narrow hash marks it’s really easy to throw to the gap. Cover 0 and playing dbs back by the first down marker gives you a chance but you’re still real susceptible to yac plays.
The key to consistent pressure is mixing looks. 3 and 4 man fronts, layering pass rush lanes, twisting, running cheetah, then showing and dropping from blitz looks. Doing all that requires guys to constantly be as fresh as possible so they can really get after it. When you try and do that stuff with out rotating especially if they other team runs with some balance the dl just gets beat up.