A suggestion for tank assassins

I made a post long ago suggesting this, and someone said that it sounded like something for preseason, so now that it's preseason where you can go crazy with changes, I'd like to suggest it again. I think this will help with the whole "tank assassin" thing and will give you a new lever you can adjust to fix things when champions who aren't meant to be building super tanky start building tanky and doing too much damage. Basically the suggestion is to give a weight cap stat to every champion, and a weight stat to every item in the game. Tanks could have the highest weight caps, while ADCs/assassins would have the least(obviously you could make exceptions). Everything else could be inbetween. After you set the weight caps, for the item weight values, offensive items should be low in weight, and anything with defensive values could be higher in weight depending on how defensive it is. After you do this, when a champion buys over their weight limit, they get move speed reductions depending on how far over the weight limit they are. For example, say the weight cap for this assassin is like 9(the numbers are just examples), each pure offensive item has a weight value of 1, while semi defensive items have a weight of 2, and full defensive items have a weight of 3. Say the assassin went full tank, maybe got up to 15 weight value. Now they're 6 over their weight cap, so they lose 60 move speed(I used 10x weight over the weight cap because it needed to be a decent number in this example, obviously with the right numbers it'd probably be a totally different formula). This doesn't kill the tank assassin outright, it just makes it harder for them to stick to you like glue(as assassins usually have very high sticking potential) as a tank, while also making it harder for them to just go in and go back out(another thing assassins have that makes them overly powerful as tanks). If they build tank, they actually have to commit, and can be kited, which I would say is what a tank should be like. This would obviously have liberties taken to where you can still build defensively without going over the weight limit, it'd just be there for someone that isn't meant to be tanky to build one offensive item and full tank and be an all powerful champion that you just can't get away from and can't be killed easily at the same time, while also making it harder for them to just "nope" out of there if things become unfavorable.