7.21 Jungle Health vs Armor Seals?

Do I chose Armor or Health / Health Per Lvl Seals? I look at rune pages of other junglers, and they are using health per lvl. I am low elo (b1) and 75% of my games don't even make it past lvl 16 so I wouldn't get the full use of per lvl any runes.So far i have kept my armor seals, but i would like to know the reason to use health / health per lvl seals and if it is used only for certain type of champions which ones?