The problem with AP assassins and what is troublesome of champions like Eve

So Eve's been out for a few day and I have noticed something of a problem with champions like Fizz, Leblanc, Eve and Nidalee. They all need to proc a mark to be able to assassinate their targets (Nid's spear, LB passive, Fizz's ult, Eve's W). While by itself there is no problem there is no problem with the mechanic, when it is the only way for a champion to function I think a problem starts emerging. Fizz for example is frustrating for a lot of people, because if he land ult you are almost always dead but if not unless you are feed you aren't killing any one. Champions like Nidalee and Ekko on the other hand although they do have passives to proc for massive damage, also have other uses in their kit outside of it (Ekko can fish for stuns and nidalee heal and fish for spears.

The problem I see with Eve is that she is a pure assassin that is very straightforward outside of playing with her camo positioning. You either proc the charm and Land your Q and kill the target, or you don't and you don't have enough damage to kill it. She also can't reliably go in without her ult to escape; this is fine if the ult was on a lower CD, but because so much of Eve's damage budget is tied to it can't currently. I think adjusting the damage of her ult and changing how the charm/empowered E work might benefit Eve a lot

For example, one idea is that the charm procs if Eve stays in sight of the enemy he marked for 1.5 seconds (so she has to expose herself without attacking but can go for the kill faster without relying so much on landing her abilities. Also, she could have the range on empowered E be longer/do more damage and reduce the CD and damage from the ult to compensate. This way she can choose between a quicker in and out to kill or more damage at the risk of exposing herself