Assassins dont need delayed burst
But weaker burst followed up with sustained damage that is effective vs squishies targets that is weaker the more durable the target is. IMO it solves issue of assassins one shotting carries without counter play but still gives squishy targets a (minor) fighting chance in a situation that still favors assassins the more out of position a target is.
Ideally a somewhere between 60-70 percent burst with the sustained damage being the rest.