how necessary is the slow on randuins?

just wanted to read some general opinions.

i wonder if it would make sense to replace the movement speed slow against an active specifically tageted to protect you from auto attacks instead. what if instead of an aoe slow, it would instead massively increase the cold steel passive for a couple of seconds?

for example something like enemies attacking you have their total attack speed reduced by 30% for 2 seconds. with the duration of the active scaling with resistances, similar to how the current slow active duration used to get longer the more armor/mr you have.

reason im asking is, because riot has recently gone into the direction of giving the armor items each a very specific nieche.

roam and engage waveclear defense against auto attacks

while the aoe slow is useful without a doubt, it doesnt really fit into what randuins is trying to accomplish, unless it would also slow attack speed.

maybe the aoe slow active would be better off on another item. maybe another new armor/health item specifically focused around anti kiting.