loose hp on killing low levels?

Hello,
You know you win honor points when killing players, but not low level players, they dont't give you hp. Because it is honorless to kill low levels with 1 shot.
But, why not loose hp? Lower level, can make you loose more hp. Forexample lvl40, if he kills lvl20, loose 200hp, if he kills lvl10 loose 300hp.
This would be soo fair.
Now i know you want to say "this is the game, they can kill you", it is okay,and it is okay and the game also to loose hp too because this is very honorless and has no fun at all. Killing very low level is not fait but low levels must run again and again because of 1 shot.
This has no fun at all.
What do you think?

This is also realistic because if a big warrior kills small weak guy, he would loose his honor really and people wouldn't respect him would they?

Can easily kill 10 lowbies of any level without making big impact on HP. Then you just use a spell, or eat for few seconds. It's a mere slight inconvenience. An inconvenience most classes don't have to worry about at all thanks to selfheals.

If you meant the HP is taken from max HP, people would all of a sudden be running multibox with 4 x level 68/69 meat shields.

Sorry if i couldn't explain well.
I meant honor points by HP, which you have on battlegrounds or killing players in realms.
If level 50 kills level20 player, then he can loose honor points

Attacking players of the opposing faction, no matter the level difference and without any mechanics repercussion, is part of a WoW PvP server.