Best Last Hit on large minions lane

Hi pleople, would like to propose a better last hit on minions large lane. I know you've more than once missed minion cannon that is very difficult to estimate their life compared to the other minions. And surely you will keep losing like me (Losing minion that gives more gold) =(

My proposal is to make the visibly larger life.

Here today. http://i.imgur.com/3eclQ7x.jpg

And as improve. http://i.imgur.com/4vYrRQ1.jpg

Surely not lose so valuable that gold =(

http://i.imgur.com/ARJT2M7.jpg

http://i.imgur.com/Dvy4FGl.jpg

Thank you for your attention. I hope Riot response. Help me like giving me please. And sorry if my English is bad, I speak Spanish.

PD: I post this in the PBE but I do not mind XD